[libc-commits] [lld] [lldb] [compiler-rt] [libc] [llvm] [libcxx] [libclc] [flang] [clang-tools-extra] [clang] [libc++] Ensure that `std::expected` has no tail padding (PR #69673)
Louis Dionne via libc-commits
libc-commits at lists.llvm.org
Mon Jan 22 06:03:45 PST 2024
Jan =?utf-8?q?Kokemüller?= <jan.kokemueller at gmail.com>,
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Jan =?utf-8?q?Kokemüller?= <jan.kokemueller at gmail.com>,Louis Dionne
<ldionne.2 at gmail.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/69673 at github.com>
https://github.com/ldionne updated https://github.com/llvm/llvm-project/pull/69673
>From 03e2f9a58a5ceb373527001083f805c71e91880c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sun, 15 Oct 2023 22:09:51 +0200
Subject: [PATCH 01/55] ensure that expected has no tail padding
---
libcxx/include/__expected/expected.h | 47 +++++++++++++++++++---------
1 file changed, 33 insertions(+), 14 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 9f36c41b78edfd..c5ff588014bbbb 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -18,6 +18,7 @@
#include <__memory/addressof.h>
#include <__memory/construct_at.h>
#include <__type_traits/conjunction.h>
+#include <__type_traits/datasizeof.h>
#include <__type_traits/disjunction.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_assignable.h>
@@ -123,7 +124,7 @@ class expected {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __other) noexcept(
- is_nothrow_copy_constructible_v<_Tp> && is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
: __union_(__other.__has_val_, __other.__union_), __has_val_(__other.__has_val_) {}
@@ -134,7 +135,7 @@ class expected {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __other) noexcept(
- is_nothrow_move_constructible_v<_Tp> && is_nothrow_move_constructible_v<_Err>)
+ is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
: __union_(__other.__has_val_, std::move(__other.__union_)), __has_val_(__other.__has_val_) {}
@@ -175,15 +176,15 @@ class expected {
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _Up&, _Tp> ||
!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __other) noexcept(
- is_nothrow_constructible_v<_Tp, const _Up&> &&
- is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
+ is_nothrow_constructible_v<_Tp, const _Up&>&&
+ is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
: __union_(__other.__has_val_, __other.__union_), __has_val_(__other.__has_val_) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
- is_nothrow_constructible_v<_Tp, _Up> && is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
+ is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
: __union_(__other.__has_val_, std::move(__other.__union_)), __has_val_(__other.__has_val_) {}
template <class _Up = _Tp>
@@ -275,8 +276,8 @@ class expected {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected& __rhs) noexcept(
- is_nothrow_copy_assignable_v<_Tp> && is_nothrow_copy_constructible_v<_Tp> && is_nothrow_copy_assignable_v<_Err> &&
- is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_assignable_v<_Tp>&& is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_assignable_v<_Err>&&
+ is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Tp> && is_copy_constructible_v<_Tp> && is_copy_assignable_v<_Err> &&
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -296,8 +297,8 @@ class expected {
}
_LIBCPP_HIDE_FROM_ABI constexpr expected&
- operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Tp> && is_nothrow_move_constructible_v<_Tp> &&
- is_nothrow_move_assignable_v<_Err> && is_nothrow_move_constructible_v<_Err>)
+ operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Tp>&& is_nothrow_move_constructible_v<_Tp>&&
+ is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_assignable_v<_Tp> && is_move_constructible_v<_Err> &&
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -396,8 +397,8 @@ class expected {
public:
// [expected.object.swap], swap
_LIBCPP_HIDE_FROM_ABI constexpr void
- swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Tp> && is_nothrow_swappable_v<_Tp> &&
- is_nothrow_move_constructible_v<_Err> && is_nothrow_swappable_v<_Err>)
+ swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Tp>&& is_nothrow_swappable_v<_Tp>&&
+ is_nothrow_move_constructible_v<_Err>&& is_nothrow_swappable_v<_Err>)
requires(is_swappable_v<_Tp> && is_swappable_v<_Err> && is_move_constructible_v<_Tp> &&
is_move_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -912,8 +913,17 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
+ _LIBCPP_HIDE_FROM_ABI static constexpr auto __calculate_padding() {
+ struct __calc_expected {
+ _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
+ bool __has_val_;
+ };
+ return sizeof(__calc_expected) - __libcpp_datasizeof<__calc_expected>::value;
+ }
+
_LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
bool __has_val_;
+ char __padding_[__calculate_padding()]{};
};
template <class _Tp, class _Err>
@@ -1036,7 +1046,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected& __rhs) noexcept(
- is_nothrow_copy_assignable_v<_Err> && is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_assignable_v<_Err>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Err> && is_copy_constructible_v<_Err>)
{
if (__has_val_) {
@@ -1058,7 +1068,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(expected&&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected&
- operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err> && is_nothrow_move_constructible_v<_Err>)
+ operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)
{
if (__has_val_) {
@@ -1110,7 +1120,7 @@ class expected<_Tp, _Err> {
// [expected.void.swap], swap
_LIBCPP_HIDE_FROM_ABI constexpr void
- swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Err> && is_nothrow_swappable_v<_Err>)
+ swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>&& is_nothrow_swappable_v<_Err>)
requires(is_swappable_v<_Err> && is_move_constructible_v<_Err>)
{
auto __swap_val_unex_impl = [&](expected& __with_val, expected& __with_err) {
@@ -1504,8 +1514,17 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
+ _LIBCPP_HIDE_FROM_ABI static constexpr auto __calculate_padding() {
+ struct __calc_expected {
+ _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
+ bool __has_val_;
+ };
+ return sizeof(__calc_expected) - __libcpp_datasizeof<__calc_expected>::value;
+ }
+
_LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
bool __has_val_;
+ char __padding_[__calculate_padding()]{};
};
_LIBCPP_END_NAMESPACE_STD
>From 83400babff821e0620148c16589f2046e420b441 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 20 Oct 2023 19:40:18 +0200
Subject: [PATCH 02/55] handle GCC's warning in __libcpp_datasizeof
---
libcxx/include/__type_traits/datasizeof.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/libcxx/include/__type_traits/datasizeof.h b/libcxx/include/__type_traits/datasizeof.h
index 3a8b1516010731..197403ea0429dd 100644
--- a/libcxx/include/__type_traits/datasizeof.h
+++ b/libcxx/include/__type_traits/datasizeof.h
@@ -55,6 +55,7 @@ struct __libcpp_datasizeof {
// the use as an extension.
_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Winvalid-offsetof")
+ _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Winvalid-offsetof")
static const size_t value = offsetof(_FirstPaddingByte<>, __first_padding_byte_);
_LIBCPP_DIAGNOSTIC_POP
#endif // __has_extension(datasizeof)
>From 115203b847d1145b1824e240abb98b99843219f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 20 Oct 2023 19:53:22 +0200
Subject: [PATCH 03/55] implement different approach to padding calculation
This tries to fix two issues:
- There should be no artificial padding if the parameter type(s) don't
need it, for example if they have no tail padding
- Prevent the padding array being zero length
---
libcxx/include/__expected/expected.h | 52 +++++++++++++++++-----------
1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index c5ff588014bbbb..b8c06646804a1e 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -89,6 +89,34 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
+template <size_t __Padding>
+struct __expected_padding {
+ using type = char[__Padding];
+};
+
+template <>
+struct __expected_padding<0> {
+ using type = struct {};
+};
+
+template <class _Union>
+_LIBCPP_HIDE_FROM_ABI constexpr size_t __expected_calculate_padding() {
+ struct __calc_expected {
+ _LIBCPP_NO_UNIQUE_ADDRESS _Union __union_;
+ bool __has_val_;
+ };
+
+ size_t __datasize = __libcpp_datasizeof<__calc_expected>::value;
+ return sizeof(_Union) < __datasize ? 0 : sizeof(_Union) - __datasize;
+}
+
+// An object of this type must be the last member of the `expected` class to
+// ensure `expected`'s datasize is large enough to fit the parameter type(s).
+// It should be value-initialized so it is safe to copy when `expected`'s
+// copy operators are invoked.
+template <typename _Union>
+using __expected_padding_t = __expected_padding<__expected_calculate_padding<_Union>()>::type;
+
template <class _Tp, class _Err>
class expected {
static_assert(!is_reference_v<_Tp> && !is_function_v<_Tp> && !is_same_v<remove_cv_t<_Tp>, in_place_t> &&
@@ -913,17 +941,9 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- _LIBCPP_HIDE_FROM_ABI static constexpr auto __calculate_padding() {
- struct __calc_expected {
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
- bool __has_val_;
- };
- return sizeof(__calc_expected) - __libcpp_datasizeof<__calc_expected>::value;
- }
-
_LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
- bool __has_val_;
- char __padding_[__calculate_padding()]{};
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_padding_t<__union_t<_Tp, _Err>> __padding_{};
};
template <class _Tp, class _Err>
@@ -1514,17 +1534,9 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- _LIBCPP_HIDE_FROM_ABI static constexpr auto __calculate_padding() {
- struct __calc_expected {
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
- bool __has_val_;
- };
- return sizeof(__calc_expected) - __libcpp_datasizeof<__calc_expected>::value;
- }
-
_LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
- bool __has_val_;
- char __padding_[__calculate_padding()]{};
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_padding_t<__union_t<_Err>> __padding_{};
};
_LIBCPP_END_NAMESPACE_STD
>From 1d25139a2816bf61e431766844ef2c3959d241c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 20 Oct 2023 19:56:59 +0200
Subject: [PATCH 04/55] add tests
---
.../no_unique_address.compile.pass.cpp | 17 +++++++++++++++++
.../no_unique_address.compile.pass.cpp | 15 +++++++++++++++
2 files changed, 32 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index c8c217054ae6c4..06f597d54871ee 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -26,6 +26,13 @@ struct B : public A {
virtual ~B() = default;
};
+struct BoolWithPadding {
+ explicit operator bool() { return b; }
+
+private:
+ alignas(1024) bool b = false;
+};
+
static_assert(sizeof(std::expected<Empty, Empty>) == sizeof(bool));
static_assert(sizeof(std::expected<Empty, A>) == 2 * sizeof(int) + alignof(std::expected<Empty, A>));
static_assert(sizeof(std::expected<Empty, B>) == sizeof(B) + alignof(std::expected<Empty, B>));
@@ -33,3 +40,13 @@ static_assert(sizeof(std::expected<A, Empty>) == 2 * sizeof(int) + alignof(std::
static_assert(sizeof(std::expected<A, A>) == 2 * sizeof(int) + alignof(std::expected<A, A>));
static_assert(sizeof(std::expected<B, Empty>) == sizeof(B) + alignof(std::expected<B, Empty>));
static_assert(sizeof(std::expected<B, B>) == sizeof(B) + alignof(std::expected<B, B>));
+
+// Check that `expected`'s datasize is large enough for the parameter type(s).
+static_assert(sizeof(std::expected<BoolWithPadding, Empty>) ==
+ std::__libcpp_datasizeof<std::expected<BoolWithPadding, Empty>>::value);
+static_assert(sizeof(std::expected<Empty, BoolWithPadding>) ==
+ std::__libcpp_datasizeof<std::expected<Empty, BoolWithPadding>>::value);
+
+// In this case, there should be tail padding in the `expected` because `A`
+// itself does _not_ have tail padding.
+static_assert(sizeof(std::expected<A, A>) > std::__libcpp_datasizeof<std::expected<A, A>>::value);
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index dc59a6228386bc..29cf8dff0d2b28 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -26,6 +26,21 @@ struct B : public A {
virtual ~B() = default;
};
+struct BoolWithPadding {
+ explicit operator bool() { return b; }
+
+private:
+ alignas(1024) bool b = false;
+};
+
static_assert(sizeof(std::expected<void, Empty>) == sizeof(bool));
static_assert(sizeof(std::expected<void, A>) == 2 * sizeof(int) + alignof(std::expected<void, A>));
static_assert(sizeof(std::expected<void, B>) == sizeof(B) + alignof(std::expected<void, B>));
+
+// Check that `expected`'s datasize is large enough for the parameter type(s).
+static_assert(sizeof(std::expected<void, BoolWithPadding>) ==
+ std::__libcpp_datasizeof<std::expected<void, BoolWithPadding>>::value);
+
+// In this case, there should be tail padding in the `expected` because `A`
+// itself does _not_ have tail padding.
+static_assert(sizeof(std::expected<void, A>) > std::__libcpp_datasizeof<std::expected<void, A>>::value);
>From d2e4c35ed196729a5315d5126e547b04aa14dd78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 20 Oct 2023 22:02:20 +0200
Subject: [PATCH 05/55] implement repr/compact_pair approach
---
libcxx/include/__expected/expected.h | 468 +++++++++---------
.../no_unique_address.compile.pass.cpp | 1 +
.../no_unique_address.compile.pass.cpp | 1 +
3 files changed, 237 insertions(+), 233 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index b8c06646804a1e..8f859ee5d37aff 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -89,33 +89,11 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-template <size_t __Padding>
-struct __expected_padding {
- using type = char[__Padding];
-};
-
-template <>
-struct __expected_padding<0> {
- using type = struct {};
-};
-
template <class _Union>
-_LIBCPP_HIDE_FROM_ABI constexpr size_t __expected_calculate_padding() {
- struct __calc_expected {
- _LIBCPP_NO_UNIQUE_ADDRESS _Union __union_;
- bool __has_val_;
- };
-
- size_t __datasize = __libcpp_datasizeof<__calc_expected>::value;
- return sizeof(_Union) < __datasize ? 0 : sizeof(_Union) - __datasize;
-}
-
-// An object of this type must be the last member of the `expected` class to
-// ensure `expected`'s datasize is large enough to fit the parameter type(s).
-// It should be value-initialized so it is safe to copy when `expected`'s
-// copy operators are invoked.
-template <typename _Union>
-using __expected_padding_t = __expected_padding<__expected_calculate_padding<_Union>()>::type;
+struct __expected_repr {
+ [[no_unique_address]] _Union __union_;
+ [[no_unique_address]] bool __has_val_;
+};
template <class _Tp, class _Err>
class expected {
@@ -142,7 +120,7 @@ class expected {
// [expected.object.ctor], constructors
_LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept(is_nothrow_default_constructible_v<_Tp>) // strengthened
requires is_default_constructible_v<_Tp>
- : __union_(std::in_place), __has_val_(true) {}
+ : __repr_{.__union_{std::in_place}, .__has_val_ = true} {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -155,7 +133,8 @@ class expected {
is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
- : __union_(__other.__has_val_, __other.__union_), __has_val_(__other.__has_val_) {}
+ : __repr_{.__union_{__other.__repr_.__has_val_, __other.__repr_.__union_},
+ .__has_val_ = __other.__repr_.__has_val_} {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
@@ -166,7 +145,8 @@ class expected {
is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
- : __union_(__other.__has_val_, std::move(__other.__union_)), __has_val_(__other.__has_val_) {}
+ : __repr_{.__union_{__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)},
+ .__has_val_ = __other.__repr_.__has_val_} {}
private:
template <class _Up, class _OtherErr, class _UfQual, class _OtherErrQual>
@@ -191,12 +171,12 @@ class expected {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_in_place_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(true) {}
+ : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = true} {}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = false} {}
public:
template <class _Up, class _OtherErr>
@@ -206,14 +186,16 @@ class expected {
expected(const expected<_Up, _OtherErr>& __other) noexcept(
is_nothrow_constructible_v<_Tp, const _Up&>&&
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __union_(__other.__has_val_, __other.__union_), __has_val_(__other.__has_val_) {}
+ : __repr_{.__union_{__other.__repr_.__has_val_, __other.__repr_.__union_},
+ .__has_val_ = __other.__repr_.__has_val_} {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __union_(__other.__has_val_, std::move(__other.__union_)), __has_val_(__other.__has_val_) {}
+ : __repr_{.__union_{__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)},
+ .__has_val_ = __other.__repr_.__has_val_} {}
template <class _Up = _Tp>
requires(!is_same_v<remove_cvref_t<_Up>, in_place_t> && !is_same_v<expected, remove_cvref_t<_Up>> &&
@@ -221,43 +203,43 @@ class expected {
(!is_same_v<remove_cv_t<_Tp>, bool> || !__is_std_expected<remove_cvref_t<_Up>>::value))
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp>)
expected(_Up&& __u) noexcept(is_nothrow_constructible_v<_Tp, _Up>) // strengthened
- : __union_(std::in_place, std::forward<_Up>(__u)), __has_val_(true) {}
+ : __repr_{.__union_{std::in_place, std::forward<_Up>(__u)}, .__has_val_ = true} {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __union_(std::unexpect, __unex.error()), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, __unex.error()}, .__has_val_ = false} {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __union_(std::unexpect, std::move(__unex.error())), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, std::move(__unex.error())}, .__has_val_ = false} {}
template <class... _Args>
requires is_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, _Args...>) // strengthened
- : __union_(std::in_place, std::forward<_Args>(__args)...), __has_val_(true) {}
+ : __repr_{.__union_{std::in_place, std::forward<_Args>(__args)...}, .__has_val_ = true} {}
template <class _Up, class... _Args>
requires is_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>) // strengthened
- : __union_(std::in_place, __il, std::forward<_Args>(__args)...), __has_val_(true) {}
+ : __repr_{.__union_{std::in_place, __il, std::forward<_Args>(__args)...}, .__has_val_ = true} {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __union_(std::unexpect, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __union_(std::unexpect, __il, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, __il, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
// [expected.object.dtor], destructor
@@ -268,10 +250,10 @@ class expected {
_LIBCPP_HIDE_FROM_ABI constexpr ~expected()
requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
{
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
+ if (__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__val_));
} else {
- std::destroy_at(std::addressof(__union_.__unex_));
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
}
}
@@ -310,17 +292,17 @@ class expected {
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (__has_val_ && __rhs.__has_val_) {
- __union_.__val_ = __rhs.__union_.__val_;
- } else if (__has_val_) {
- __reinit_expected(__union_.__unex_, __union_.__val_, __rhs.__union_.__unex_);
- } else if (__rhs.__has_val_) {
- __reinit_expected(__union_.__val_, __union_.__unex_, __rhs.__union_.__val_);
+ if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
+ __repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
+ } else if (__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
+ } else if (__rhs.__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
} else {
- __union_.__unex_ = __rhs.__union_.__unex_;
+ __repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
// note: only reached if no exception+rollback was done inside __reinit_expected
- __has_val_ = __rhs.__has_val_;
+ __repr_.__has_val_ = __rhs.__repr_.__has_val_;
return *this;
}
@@ -331,17 +313,17 @@ class expected {
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (__has_val_ && __rhs.__has_val_) {
- __union_.__val_ = std::move(__rhs.__union_.__val_);
- } else if (__has_val_) {
- __reinit_expected(__union_.__unex_, __union_.__val_, std::move(__rhs.__union_.__unex_));
- } else if (__rhs.__has_val_) {
- __reinit_expected(__union_.__val_, __union_.__unex_, std::move(__rhs.__union_.__val_));
+ if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
+ __repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
+ } else if (__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
+ } else if (__rhs.__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
} else {
- __union_.__unex_ = std::move(__rhs.__union_.__unex_);
+ __repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
// note: only reached if no exception+rollback was done inside __reinit_expected
- __has_val_ = __rhs.__has_val_;
+ __repr_.__has_val_ = __rhs.__repr_.__has_val_;
return *this;
}
@@ -352,11 +334,11 @@ class expected {
(is_nothrow_constructible_v<_Tp, _Up> || is_nothrow_move_constructible_v<_Tp> ||
is_nothrow_move_constructible_v<_Err>))
{
- if (__has_val_) {
- __union_.__val_ = std::forward<_Up>(__v);
+ if (__repr_.__has_val_) {
+ __repr_.__union_.__val_ = std::forward<_Up>(__v);
} else {
- __reinit_expected(__union_.__val_, __union_.__unex_, std::forward<_Up>(__v));
- __has_val_ = true;
+ __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, std::forward<_Up>(__v));
+ __repr_.__has_val_ = true;
}
return *this;
}
@@ -375,11 +357,11 @@ class expected {
template <class _OtherErr>
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (__has_val_) {
- __reinit_expected(__union_.__unex_, __union_.__val_, __un.error());
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, __un.error());
+ __repr_.__has_val_ = false;
} else {
- __union_.__unex_ = __un.error();
+ __repr_.__union_.__unex_ = __un.error();
}
return *this;
}
@@ -387,11 +369,11 @@ class expected {
template <class _OtherErr>
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (__has_val_) {
- __reinit_expected(__union_.__unex_, __union_.__val_, std::move(__un.error()));
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, std::move(__un.error()));
+ __repr_.__has_val_ = false;
} else {
- __union_.__unex_ = std::move(__un.error());
+ __repr_.__union_.__unex_ = std::move(__un.error());
}
return *this;
}
@@ -399,27 +381,27 @@ class expected {
template <class... _Args>
requires is_nothrow_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
+ if (__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__val_));
} else {
- std::destroy_at(std::addressof(__union_.__unex_));
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
}
- std::construct_at(std::addressof(__union_.__val_), std::forward<_Args>(__args)...);
- __has_val_ = true;
- return __union_.__val_;
+ std::construct_at(std::addressof(__repr_.__union_.__val_), std::forward<_Args>(__args)...);
+ __repr_.__has_val_ = true;
+ return __repr_.__union_.__val_;
}
template <class _Up, class... _Args>
requires is_nothrow_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
+ if (__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__val_));
} else {
- std::destroy_at(std::addressof(__union_.__unex_));
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
}
- std::construct_at(std::addressof(__union_.__val_), __il, std::forward<_Args>(__args)...);
- __has_val_ = true;
- return __union_.__val_;
+ std::construct_at(std::addressof(__repr_.__union_.__val_), __il, std::forward<_Args>(__args)...);
+ __repr_.__has_val_ = true;
+ return __repr_.__union_.__val_;
}
public:
@@ -433,46 +415,48 @@ class expected {
{
auto __swap_val_unex_impl = [&](expected& __with_val, expected& __with_err) {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
- _Err __tmp(std::move(__with_err.__union_.__unex_));
- std::destroy_at(std::addressof(__with_err.__union_.__unex_));
+ _Err __tmp(std::move(__with_err.__repr_.__union_.__unex_));
+ std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
auto __trans = std::__make_exception_guard([&] {
- std::construct_at(std::addressof(__with_err.__union_.__unex_), std::move(__tmp));
+ std::construct_at(std::addressof(__with_err.__repr_.__union_.__unex_), std::move(__tmp));
});
- std::construct_at(std::addressof(__with_err.__union_.__val_), std::move(__with_val.__union_.__val_));
+ std::construct_at(
+ std::addressof(__with_err.__repr_.__union_.__val_), std::move(__with_val.__repr_.__union_.__val_));
__trans.__complete();
- std::destroy_at(std::addressof(__with_val.__union_.__val_));
- std::construct_at(std::addressof(__with_val.__union_.__unex_), std::move(__tmp));
+ std::destroy_at(std::addressof(__with_val.__repr_.__union_.__val_));
+ std::construct_at(std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__tmp));
} else {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
"that it can be reverted to the previous state in case an exception is thrown during swap.");
- _Tp __tmp(std::move(__with_val.__union_.__val_));
- std::destroy_at(std::addressof(__with_val.__union_.__val_));
+ _Tp __tmp(std::move(__with_val.__repr_.__union_.__val_));
+ std::destroy_at(std::addressof(__with_val.__repr_.__union_.__val_));
auto __trans = std::__make_exception_guard([&] {
- std::construct_at(std::addressof(__with_val.__union_.__val_), std::move(__tmp));
+ std::construct_at(std::addressof(__with_val.__repr_.__union_.__val_), std::move(__tmp));
});
- std::construct_at(std::addressof(__with_val.__union_.__unex_), std::move(__with_err.__union_.__unex_));
+ std::construct_at(
+ std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__with_err.__repr_.__union_.__unex_));
__trans.__complete();
- std::destroy_at(std::addressof(__with_err.__union_.__unex_));
- std::construct_at(std::addressof(__with_err.__union_.__val_), std::move(__tmp));
+ std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
+ std::construct_at(std::addressof(__with_err.__repr_.__union_.__val_), std::move(__tmp));
}
- __with_val.__has_val_ = false;
- __with_err.__has_val_ = true;
+ __with_val.__repr_.__has_val_ = false;
+ __with_err.__repr_.__has_val_ = true;
};
- if (__has_val_) {
- if (__rhs.__has_val_) {
+ if (__repr_.__has_val_) {
+ if (__rhs.__repr_.__has_val_) {
using std::swap;
- swap(__union_.__val_, __rhs.__union_.__val_);
+ swap(__repr_.__union_.__val_, __rhs.__repr_.__union_.__val_);
} else {
__swap_val_unex_impl(*this, __rhs);
}
} else {
- if (__rhs.__has_val_) {
+ if (__rhs.__repr_.__has_val_) {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(__union_.__unex_, __rhs.__union_.__unex_);
+ swap(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
}
}
}
@@ -485,105 +469,115 @@ class expected {
// [expected.object.obs], observers
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp* operator->() const noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(__union_.__val_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator->() noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(__union_.__val_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator* requires the expected to contain a value");
- return __union_.__val_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return __repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator* requires the expected to contain a value");
- return __union_.__val_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return __repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(__union_.__val_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(__union_.__val_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(__repr_.__union_.__val_);
}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __repr_.__has_val_; }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __repr_.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& value() const& {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!__has_val_) {
+ if (!__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return __union_.__val_;
+ return __repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!__has_val_) {
+ if (!__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return __union_.__val_;
+ return __repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& value() const&& {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!__has_val_) {
+ if (!__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(__union_.__val_);
+ return std::move(__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!__has_val_) {
+ if (!__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(__union_.__val_);
+ return std::move(__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return __union_.__unex_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return __repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return __union_.__unex_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return __repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__union_.__unex_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(__repr_.__union_.__unex_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__union_.__unex_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(__repr_.__union_.__unex_);
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) const& {
static_assert(is_copy_constructible_v<_Tp>, "value_type has to be copy constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return __has_val_ ? __union_.__val_ : static_cast<_Tp>(std::forward<_Up>(__v));
+ return __repr_.__has_val_ ? __repr_.__union_.__val_ : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
static_assert(is_move_constructible_v<_Tp>, "value_type has to be move constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return __has_val_ ? std::move(__union_.__val_) : static_cast<_Tp>(std::forward<_Up>(__v));
+ return __repr_.__has_val_ ? std::move(__repr_.__union_.__val_) : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up = _Err>
@@ -613,7 +607,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), __union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
}
return _Up(unexpect, error());
}
@@ -626,7 +620,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), __union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
}
return _Up(unexpect, error());
}
@@ -640,7 +634,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
}
return _Up(unexpect, std::move(error()));
}
@@ -654,7 +648,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
}
return _Up(unexpect, std::move(error()));
}
@@ -667,7 +661,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, __union_.__val_);
+ return _Gp(in_place, __repr_.__union_.__val_);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -680,7 +674,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, __union_.__val_);
+ return _Gp(in_place, __repr_.__union_.__val_);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -694,7 +688,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(__union_.__val_));
+ return _Gp(in_place, std::move(__repr_.__union_.__val_));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -708,7 +702,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(__union_.__val_));
+ return _Gp(in_place, std::move(__repr_.__union_.__val_));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -722,9 +716,9 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __repr_.__union_.__val_);
} else {
- std::invoke(std::forward<_Func>(__f), __union_.__val_);
+ std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
return expected<_Up, _Err>();
}
}
@@ -738,9 +732,9 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __repr_.__union_.__val_);
} else {
- std::invoke(std::forward<_Func>(__f), __union_.__val_);
+ std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
return expected<_Up, _Err>();
}
}
@@ -754,9 +748,11 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(__union_.__val_));
+ __expected_construct_in_place_from_invoke_tag{},
+ std::forward<_Func>(__f),
+ std::move(__repr_.__union_.__val_));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
return expected<_Up, _Err>();
}
}
@@ -770,9 +766,11 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(__union_.__val_));
+ __expected_construct_in_place_from_invoke_tag{},
+ std::forward<_Func>(__f),
+ std::move(__repr_.__union_.__val_));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
return expected<_Up, _Err>();
}
}
@@ -784,7 +782,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, __union_.__val_);
+ return expected<_Tp, _Gp>(in_place, __repr_.__union_.__val_);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -796,7 +794,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, __union_.__val_);
+ return expected<_Tp, _Gp>(in_place, __repr_.__union_.__val_);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -808,7 +806,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(__repr_.__union_.__val_));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -821,7 +819,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(__repr_.__union_.__val_));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -831,25 +829,25 @@ class expected {
template <class _T2, class _E2>
requires(!is_void_v<_T2>)
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const expected<_T2, _E2>& __y) {
- if (__x.__has_val_ != __y.__has_val_) {
+ if (__x.__repr_.__has_val_ != __y.__repr_.__has_val_) {
return false;
} else {
- if (__x.__has_val_) {
- return __x.__union_.__val_ == __y.__union_.__val_;
+ if (__x.__repr_.__has_val_) {
+ return __x.__repr_.__union_.__val_ == __y.__repr_.__union_.__val_;
} else {
- return __x.__union_.__unex_ == __y.__union_.__unex_;
+ return __x.__repr_.__union_.__unex_ == __y.__repr_.__union_.__unex_;
}
}
}
template <class _T2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const _T2& __v) {
- return __x.__has_val_ && static_cast<bool>(__x.__union_.__val_ == __v);
+ return __x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__val_ == __v);
}
template <class _E2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __e) {
- return !__x.__has_val_ && static_cast<bool>(__x.__union_.__unex_ == __e.error());
+ return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __e.error());
}
private:
@@ -941,9 +939,7 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_padding_t<__union_t<_Tp, _Err>> __padding_{};
+ __expected_repr<__union_t<_Tp, _Err>> __repr_;
};
template <class _Tp, class _Err>
@@ -974,7 +970,7 @@ class expected<_Tp, _Err> {
using rebind = expected<_Up, error_type>;
// [expected.void.ctor], constructors
- _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __has_val_(true) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_{.__union_{}, .__has_val_ = true} {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -985,7 +981,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __rhs) noexcept(
is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Err> && !is_trivially_copy_constructible_v<_Err>)
- : __union_(__rhs.__has_val_, __rhs.__union_), __has_val_(__rhs.__has_val_) {}
+ : __repr_{.__union_{__rhs.__repr_.__has_val_, __rhs.__repr_.__union_}, .__has_val_ = __rhs.__repr_.__has_val_} {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
@@ -993,58 +989,60 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Err> && !is_trivially_move_constructible_v<_Err>)
- : __union_(__rhs.__has_val_, std::move(__rhs.__union_)), __has_val_(__rhs.__has_val_) {}
+ : __repr_{.__union_{__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)},
+ .__has_val_ = __rhs.__repr_.__has_val_} {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, const _OtherErr&>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __rhs) noexcept(
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __union_(__rhs.__has_val_, __rhs.__union_), __has_val_(__rhs.__has_val_) {}
+ : __repr_{.__union_{__rhs.__repr_.__has_val_, __rhs.__repr_.__union_}, .__has_val_ = __rhs.__repr_.__has_val_} {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __rhs) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __union_(__rhs.__has_val_, std::move(__rhs.__union_)), __has_val_(__rhs.__has_val_) {}
+ : __repr_{.__union_{__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)},
+ .__has_val_ = __rhs.__repr_.__has_val_} {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __union_(std::unexpect, __unex.error()), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, __unex.error()}, .__has_val_ = false} {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __union_(std::unexpect, std::move(__unex.error())), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, std::move(__unex.error())}, .__has_val_ = false} {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __has_val_(true) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_{.__union_{}, .__has_val_ = true} {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __union_(std::unexpect, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __union_(std::unexpect, __il, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{std::unexpect, __il, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
private:
template <class _Func>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(__expected_construct_in_place_from_invoke_tag, _Func&& __f)
- : __has_val_(true) {
+ : __repr_{.__union_{}, .__has_val_ = true} {
std::invoke(std::forward<_Func>(__f));
}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = false} {}
public:
// [expected.void.dtor], destructor
@@ -1056,8 +1054,8 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr ~expected()
requires(!is_trivially_destructible_v<_Err>)
{
- if (!__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
+ if (!__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
}
}
@@ -1069,17 +1067,17 @@ class expected<_Tp, _Err> {
is_nothrow_copy_assignable_v<_Err>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Err> && is_copy_constructible_v<_Err>)
{
- if (__has_val_) {
- if (!__rhs.__has_val_) {
- std::construct_at(std::addressof(__union_.__unex_), __rhs.__union_.__unex_);
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ if (!__rhs.__repr_.__has_val_) {
+ std::construct_at(std::addressof(__repr_.__union_.__unex_), __rhs.__repr_.__union_.__unex_);
+ __repr_.__has_val_ = false;
}
} else {
- if (__rhs.__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
- __has_val_ = true;
+ if (__rhs.__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
+ __repr_.__has_val_ = true;
} else {
- __union_.__unex_ = __rhs.__union_.__unex_;
+ __repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
}
return *this;
@@ -1091,17 +1089,17 @@ class expected<_Tp, _Err> {
operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)
{
- if (__has_val_) {
- if (!__rhs.__has_val_) {
- std::construct_at(std::addressof(__union_.__unex_), std::move(__rhs.__union_.__unex_));
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ if (!__rhs.__repr_.__has_val_) {
+ std::construct_at(std::addressof(__repr_.__union_.__unex_), std::move(__rhs.__repr_.__union_.__unex_));
+ __repr_.__has_val_ = false;
}
} else {
- if (__rhs.__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
- __has_val_ = true;
+ if (__rhs.__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
+ __repr_.__has_val_ = true;
} else {
- __union_.__unex_ = std::move(__rhs.__union_.__unex_);
+ __repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
}
return *this;
@@ -1110,11 +1108,11 @@ class expected<_Tp, _Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, const _OtherErr&> && is_assignable_v<_Err&, const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (__has_val_) {
- std::construct_at(std::addressof(__union_.__unex_), __un.error());
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ std::construct_at(std::addressof(__repr_.__union_.__unex_), __un.error());
+ __repr_.__has_val_ = false;
} else {
- __union_.__unex_ = __un.error();
+ __repr_.__union_.__unex_ = __un.error();
}
return *this;
}
@@ -1122,19 +1120,19 @@ class expected<_Tp, _Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, _OtherErr> && is_assignable_v<_Err&, _OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (__has_val_) {
- std::construct_at(std::addressof(__union_.__unex_), std::move(__un.error()));
- __has_val_ = false;
+ if (__repr_.__has_val_) {
+ std::construct_at(std::addressof(__repr_.__union_.__unex_), std::move(__un.error()));
+ __repr_.__has_val_ = false;
} else {
- __union_.__unex_ = std::move(__un.error());
+ __repr_.__union_.__unex_ = std::move(__un.error());
}
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr void emplace() noexcept {
- if (!__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
- __has_val_ = true;
+ if (!__repr_.__has_val_) {
+ std::destroy_at(std::addressof(__repr_.__union_.__unex_));
+ __repr_.__has_val_ = true;
}
}
@@ -1144,22 +1142,23 @@ class expected<_Tp, _Err> {
requires(is_swappable_v<_Err> && is_move_constructible_v<_Err>)
{
auto __swap_val_unex_impl = [&](expected& __with_val, expected& __with_err) {
- std::construct_at(std::addressof(__with_val.__union_.__unex_), std::move(__with_err.__union_.__unex_));
- std::destroy_at(std::addressof(__with_err.__union_.__unex_));
- __with_val.__has_val_ = false;
- __with_err.__has_val_ = true;
+ std::construct_at(
+ std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__with_err.__repr_.__union_.__unex_));
+ std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
+ __with_val.__repr_.__has_val_ = false;
+ __with_err.__repr_.__has_val_ = true;
};
- if (__has_val_) {
- if (!__rhs.__has_val_) {
+ if (__repr_.__has_val_) {
+ if (!__rhs.__repr_.__has_val_) {
__swap_val_unex_impl(*this, __rhs);
}
} else {
- if (__rhs.__has_val_) {
+ if (__rhs.__repr_.__has_val_) {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(__union_.__unex_, __rhs.__union_.__unex_);
+ swap(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
}
}
}
@@ -1171,46 +1170,51 @@ class expected<_Tp, _Err> {
}
// [expected.void.obs], observers
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __repr_.__has_val_; }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __repr_.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr void operator*() const noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__has_val_, "expected::operator* requires the expected to contain a value");
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() const& {
static_assert(is_copy_constructible_v<_Err>);
- if (!__has_val_) {
- std::__throw_bad_expected_access<_Err>(__union_.__unex_);
+ if (!__repr_.__has_val_) {
+ std::__throw_bad_expected_access<_Err>(__repr_.__union_.__unex_);
}
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() && {
static_assert(is_copy_constructible_v<_Err> && is_move_constructible_v<_Err>);
- if (!__has_val_) {
- std::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_));
+ if (!__repr_.__has_val_) {
+ std::__throw_bad_expected_access<_Err>(std::move(__repr_.__union_.__unex_));
}
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return __union_.__unex_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return __repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return __union_.__unex_;
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return __repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__union_.__unex_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(__repr_.__union_.__unex_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
- _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__union_.__unex_);
+ _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+ !__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(__repr_.__union_.__unex_);
}
template <class _Up = _Err>
@@ -1446,16 +1450,16 @@ class expected<_Tp, _Err> {
template <class _T2, class _E2>
requires is_void_v<_T2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const expected<_T2, _E2>& __y) {
- if (__x.__has_val_ != __y.__has_val_) {
+ if (__x.__repr_.__has_val_ != __y.__repr_.__has_val_) {
return false;
} else {
- return __x.__has_val_ || static_cast<bool>(__x.__union_.__unex_ == __y.__union_.__unex_);
+ return __x.__repr_.__has_val_ || static_cast<bool>(__x.__repr_.__union_.__unex_ == __y.__repr_.__union_.__unex_);
}
}
template <class _E2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __y) {
- return !__x.__has_val_ && static_cast<bool>(__x.__union_.__unex_ == __y.error());
+ return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __y.error());
}
private:
@@ -1534,9 +1538,7 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_padding_t<__union_t<_Err>> __padding_{};
+ __expected_repr<__union_t<_Err>> __repr_;
};
_LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index 06f597d54871ee..80209db9045b50 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -13,6 +13,7 @@
// test [[no_unique_address]] is applied to the union
#include <expected>
+#include <memory>
struct Empty {};
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index 29cf8dff0d2b28..db2e4259eb8c79 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -13,6 +13,7 @@
// test [[no_unique_address]] is applied to the union
#include <expected>
+#include <memory>
struct Empty {};
>From c48d1a6f5bb4125049ae4ad17170694990131d6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 10:52:00 +0200
Subject: [PATCH 06/55] transparently replace whole 'repr' struct on mutating
operations
---
libcxx/include/__expected/expected.h | 208 ++++++++++--------
.../no_unique_address.compile.pass.cpp | 3 +-
.../no_unique_address.compile.pass.cpp | 3 +-
3 files changed, 121 insertions(+), 93 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 8f859ee5d37aff..6f19d1ed92a555 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -89,12 +89,6 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-template <class _Union>
-struct __expected_repr {
- [[no_unique_address]] _Union __union_;
- [[no_unique_address]] bool __has_val_;
-};
-
template <class _Tp, class _Err>
class expected {
static_assert(!is_reference_v<_Tp> && !is_function_v<_Tp> && !is_same_v<remove_cv_t<_Tp>, in_place_t> &&
@@ -120,7 +114,7 @@ class expected {
// [expected.object.ctor], constructors
_LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept(is_nothrow_default_constructible_v<_Tp>) // strengthened
requires is_default_constructible_v<_Tp>
- : __repr_{.__union_{std::in_place}, .__has_val_ = true} {}
+ : __repr_(std::in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -133,8 +127,7 @@ class expected {
is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
- : __repr_{.__union_{__other.__repr_.__has_val_, __other.__repr_.__union_},
- .__has_val_ = __other.__repr_.__has_val_} {}
+ : __repr_(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
@@ -145,8 +138,7 @@ class expected {
is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
- : __repr_{.__union_{__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)},
- .__has_val_ = __other.__repr_.__has_val_} {}
+ : __repr_(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
private:
template <class _Up, class _OtherErr, class _UfQual, class _OtherErrQual>
@@ -171,12 +163,12 @@ class expected {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_in_place_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = true} {}
+ : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
public:
template <class _Up, class _OtherErr>
@@ -186,16 +178,14 @@ class expected {
expected(const expected<_Up, _OtherErr>& __other) noexcept(
is_nothrow_constructible_v<_Tp, const _Up&>&&
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_{.__union_{__other.__repr_.__has_val_, __other.__repr_.__union_},
- .__has_val_ = __other.__repr_.__has_val_} {}
+ : __repr_(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_{.__union_{__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)},
- .__has_val_ = __other.__repr_.__has_val_} {}
+ : __repr_(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
template <class _Up = _Tp>
requires(!is_same_v<remove_cvref_t<_Up>, in_place_t> && !is_same_v<expected, remove_cvref_t<_Up>> &&
@@ -203,80 +193,67 @@ class expected {
(!is_same_v<remove_cv_t<_Tp>, bool> || !__is_std_expected<remove_cvref_t<_Up>>::value))
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp>)
expected(_Up&& __u) noexcept(is_nothrow_constructible_v<_Tp, _Up>) // strengthened
- : __repr_{.__union_{std::in_place, std::forward<_Up>(__u)}, .__has_val_ = true} {}
+ : __repr_(std::in_place, std::forward<_Up>(__u)) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_{.__union_{std::unexpect, __unex.error()}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_{.__union_{std::unexpect, std::move(__unex.error())}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, std::move(__unex.error())) {}
template <class... _Args>
requires is_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, _Args...>) // strengthened
- : __repr_{.__union_{std::in_place, std::forward<_Args>(__args)...}, .__has_val_ = true} {}
+ : __repr_(std::in_place, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_{.__union_{std::in_place, __il, std::forward<_Args>(__args)...}, .__has_val_ = true} {}
+ : __repr_(std::in_place, __il, std::forward<_Args>(__args)...) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_{.__union_{std::unexpect, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_{.__union_{std::unexpect, __il, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, __il, std::forward<_Args>(__args)...) {}
// [expected.object.dtor], destructor
- _LIBCPP_HIDE_FROM_ABI constexpr ~expected()
- requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~expected()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- if (__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- }
- }
+ _LIBCPP_HIDE_FROM_ABI constexpr ~expected() = default;
private:
- template <class _T1, class _T2, class... _Args>
- _LIBCPP_HIDE_FROM_ABI static constexpr void __reinit_expected(_T1& __newval, _T2& __oldval, _Args&&... __args) {
+ template <class _Tag, class _OtherTag, class _T1, class _T2, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(_T2& __oldval, _Args&&... __args) {
if constexpr (is_nothrow_constructible_v<_T1, _Args...>) {
- std::destroy_at(std::addressof(__oldval));
- std::construct_at(std::addressof(__newval), std::forward<_Args>(__args)...);
+ std::destroy_at(&__repr_);
+ std::construct_at(&__repr_, _Tag{}, std::forward<_Args>(__args)...);
} else if constexpr (is_nothrow_move_constructible_v<_T1>) {
_T1 __tmp(std::forward<_Args>(__args)...);
- std::destroy_at(std::addressof(__oldval));
- std::construct_at(std::addressof(__newval), std::move(__tmp));
+ std::destroy_at(&__repr_);
+ std::construct_at(&__repr_, _Tag{}, std::move(__tmp));
} else {
static_assert(
is_nothrow_move_constructible_v<_T2>,
"To provide strong exception guarantee, T2 has to satisfy `is_nothrow_move_constructible_v` so that it can "
"be reverted to the previous state in case an exception is thrown during the assignment.");
_T2 __tmp(std::move(__oldval));
- std::destroy_at(std::addressof(__oldval));
- auto __trans =
- std::__make_exception_guard([&] { std::construct_at(std::addressof(__oldval), std::move(__tmp)); });
- std::construct_at(std::addressof(__newval), std::forward<_Args>(__args)...);
+ std::destroy_at(&__repr_);
+ auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, _OtherTag{}, std::move(__tmp)); });
+ std::construct_at(&__repr_, _Tag{}, std::forward<_Args>(__args)...);
__trans.__complete();
}
}
@@ -295,14 +272,14 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
} else if (__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
+ __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(
+ __repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
+ __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(
+ __repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
} else {
__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
- // note: only reached if no exception+rollback was done inside __reinit_expected
- __repr_.__has_val_ = __rhs.__repr_.__has_val_;
return *this;
}
@@ -316,14 +293,14 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
} else if (__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
+ __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(
+ __repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
+ __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(
+ __repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
} else {
__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
- // note: only reached if no exception+rollback was done inside __reinit_expected
- __repr_.__has_val_ = __rhs.__repr_.__has_val_;
return *this;
}
@@ -337,8 +314,7 @@ class expected {
if (__repr_.__has_val_) {
__repr_.__union_.__val_ = std::forward<_Up>(__v);
} else {
- __reinit_expected(__repr_.__union_.__val_, __repr_.__union_.__unex_, std::forward<_Up>(__v));
- __repr_.__has_val_ = true;
+ __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
}
return *this;
}
@@ -358,8 +334,7 @@ class expected {
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
if (__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, __un.error());
- __repr_.__has_val_ = false;
+ __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
} else {
__repr_.__union_.__unex_ = __un.error();
}
@@ -370,8 +345,7 @@ class expected {
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
if (__repr_.__has_val_) {
- __reinit_expected(__repr_.__union_.__unex_, __repr_.__union_.__val_, std::move(__un.error()));
- __repr_.__has_val_ = false;
+ __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
} else {
__repr_.__union_.__unex_ = std::move(__un.error());
}
@@ -381,26 +355,16 @@ class expected {
template <class... _Args>
requires is_nothrow_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
- if (__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- }
- std::construct_at(std::addressof(__repr_.__union_.__val_), std::forward<_Args>(__args)...);
- __repr_.__has_val_ = true;
+ std::destroy_at(&__repr_);
+ std::construct_at(&__repr_, std::in_place, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
template <class _Up, class... _Args>
requires is_nothrow_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
- if (__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- }
- std::construct_at(std::addressof(__repr_.__union_.__val_), __il, std::forward<_Args>(__args)...);
- __repr_.__has_val_ = true;
+ std::destroy_at(&__repr_);
+ std::construct_at(&__repr_, std::in_place, __il, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
@@ -413,35 +377,31 @@ class expected {
is_move_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- auto __swap_val_unex_impl = [&](expected& __with_val, expected& __with_err) {
+ auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
_Err __tmp(std::move(__with_err.__repr_.__union_.__unex_));
- std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
+ std::destroy_at(&__with_err.__repr_);
auto __trans = std::__make_exception_guard([&] {
- std::construct_at(std::addressof(__with_err.__repr_.__union_.__unex_), std::move(__tmp));
+ std::construct_at(&__with_err.__repr_, std::unexpect, std::move(__tmp));
});
- std::construct_at(
- std::addressof(__with_err.__repr_.__union_.__val_), std::move(__with_val.__repr_.__union_.__val_));
+ std::construct_at(&__with_err.__repr_, std::in_place, std::move(__with_val.__repr_.__union_.__val_));
__trans.__complete();
- std::destroy_at(std::addressof(__with_val.__repr_.__union_.__val_));
- std::construct_at(std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__tmp));
+ std::destroy_at(&__with_val.__repr_);
+ std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__tmp));
} else {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
"that it can be reverted to the previous state in case an exception is thrown during swap.");
_Tp __tmp(std::move(__with_val.__repr_.__union_.__val_));
- std::destroy_at(std::addressof(__with_val.__repr_.__union_.__val_));
+ std::destroy_at(&__with_val.__repr_);
auto __trans = std::__make_exception_guard([&] {
- std::construct_at(std::addressof(__with_val.__repr_.__union_.__val_), std::move(__tmp));
+ std::construct_at(&__with_val.__repr_, std::in_place, std::move(__tmp));
});
- std::construct_at(
- std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__with_err.__repr_.__union_.__unex_));
+ std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
__trans.__complete();
- std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
- std::construct_at(std::addressof(__with_err.__repr_.__union_.__val_), std::move(__tmp));
+ std::destroy_at(&__with_err.__repr_);
+ std::construct_at(&__with_err.__repr_, std::in_place, std::move(__tmp));
}
- __with_val.__repr_.__has_val_ = false;
- __with_err.__repr_.__has_val_ = true;
};
if (__repr_.__has_val_) {
@@ -939,7 +899,73 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- __expected_repr<__union_t<_Tp, _Err>> __repr_;
+ struct __expected_repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::in_place_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _Args&&... __args)
+ : __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
+ is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
+ is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ if (__has_val_) {
+ std::destroy_at(std::addressof(__union_.__val_));
+ } else {
+ std::destroy_at(std::addressof(__union_.__unex_));
+ }
+ }
+
+ private:
+ template <class _Up, class _OtherErr>
+ friend class expected;
+
+ [[no_unique_address]] __union_t<_Tp, _Err> __union_;
+ [[no_unique_address]] bool __has_val_;
+ };
+
+ __expected_repr __repr_;
+};
+
+template <class _Union>
+struct __expected_repr {
+ [[no_unique_address]] _Union __union_;
+ [[no_unique_address]] bool __has_val_;
};
template <class _Tp, class _Err>
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index 80209db9045b50..8eeec70ff0e424 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -50,4 +50,5 @@ static_assert(sizeof(std::expected<Empty, BoolWithPadding>) ==
// In this case, there should be tail padding in the `expected` because `A`
// itself does _not_ have tail padding.
-static_assert(sizeof(std::expected<A, A>) > std::__libcpp_datasizeof<std::expected<A, A>>::value);
+// XXX
+// static_assert(sizeof(std::expected<A, A>) > std::__libcpp_datasizeof<std::expected<A, A>>::value);
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index db2e4259eb8c79..2129aa7b2405c7 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -44,4 +44,5 @@ static_assert(sizeof(std::expected<void, BoolWithPadding>) ==
// In this case, there should be tail padding in the `expected` because `A`
// itself does _not_ have tail padding.
-static_assert(sizeof(std::expected<void, A>) > std::__libcpp_datasizeof<std::expected<void, A>>::value);
+// XXX
+// static_assert(sizeof(std::expected<void, A>) > std::__libcpp_datasizeof<std::expected<void, A>>::value);
>From 8c26bb75c1b1b30ae98f65157b39362dd7add380 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 11:39:31 +0200
Subject: [PATCH 07/55] do the same for 'expected<void>'
---
libcxx/include/__expected/expected.h | 151 +++++++++++++++++----------
1 file changed, 95 insertions(+), 56 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 6f19d1ed92a555..a2417d4802a079 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -843,7 +843,7 @@ class expected {
requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
= default;
- // the expected's destructor handles this
+ // the __expected_repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
_ValueType __val_;
@@ -890,7 +890,7 @@ class expected {
requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
= default;
- // the expected's destructor handles this
+ // the __expected_repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(!is_trivially_destructible_v<_ValueType> || !is_trivially_destructible_v<_ErrorType>)
{}
@@ -952,7 +952,7 @@ class expected {
}
private:
- template <class _Up, class _OtherErr>
+ template <class, class>
friend class expected;
[[no_unique_address]] __union_t<_Tp, _Err> __union_;
@@ -962,12 +962,6 @@ class expected {
__expected_repr __repr_;
};
-template <class _Union>
-struct __expected_repr {
- [[no_unique_address]] _Union __union_;
- [[no_unique_address]] bool __has_val_;
-};
-
template <class _Tp, class _Err>
requires is_void_v<_Tp>
class expected<_Tp, _Err> {
@@ -996,7 +990,7 @@ class expected<_Tp, _Err> {
using rebind = expected<_Up, error_type>;
// [expected.void.ctor], constructors
- _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_{.__union_{}, .__has_val_ = true} {}
+ _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_(std::in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -1007,7 +1001,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __rhs) noexcept(
is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Err> && !is_trivially_copy_constructible_v<_Err>)
- : __repr_{.__union_{__rhs.__repr_.__has_val_, __rhs.__repr_.__union_}, .__has_val_ = __rhs.__repr_.__has_val_} {}
+ : __repr_(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
@@ -1015,78 +1009,82 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Err> && !is_trivially_move_constructible_v<_Err>)
- : __repr_{.__union_{__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)},
- .__has_val_ = __rhs.__repr_.__has_val_} {}
+ : __repr_(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, const _OtherErr&>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __rhs) noexcept(
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_{.__union_{__rhs.__repr_.__has_val_, __rhs.__repr_.__union_}, .__has_val_ = __rhs.__repr_.__has_val_} {}
+ : __repr_(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __rhs) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_{.__union_{__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)},
- .__has_val_ = __rhs.__repr_.__has_val_} {}
+ : __repr_(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_{.__union_{std::unexpect, __unex.error()}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_{.__union_{std::unexpect, std::move(__unex.error())}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, std::move(__unex.error())) {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_{.__union_{}, .__has_val_ = true} {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_(std::in_place) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_{.__union_{std::unexpect, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_{.__union_{std::unexpect, __il, std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(std::unexpect, __il, std::forward<_Args>(__args)...) {}
private:
template <class _Func>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(__expected_construct_in_place_from_invoke_tag, _Func&& __f)
- : __repr_{.__union_{}, .__has_val_ = true} {
+ : __repr_(std::in_place) {
std::invoke(std::forward<_Func>(__f));
}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_{.__union_{__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...}, .__has_val_ = false} {}
+ : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
public:
// [expected.void.dtor], destructor
- _LIBCPP_HIDE_FROM_ABI constexpr ~expected()
- requires is_trivially_destructible_v<_Err>
- = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr ~expected() = default;
- _LIBCPP_HIDE_FROM_ABI constexpr ~expected()
- requires(!is_trivially_destructible_v<_Err>)
- {
- if (!__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- }
+private:
+ // precondition: has_value()
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(std::unexpect_t, _Args&&... __args) {
+ std::destroy_at(&__repr_);
+ auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, std::in_place); });
+ std::construct_at(&__repr_, std::unexpect, std::forward<_Args>(__args)...);
+ __trans.__complete();
}
- // [expected.void.assign], assignment
+ // precondition: !has_value()
+ _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(std::in_place_t) {
+ std::destroy_at(&__repr_);
+ std::construct_at(&__repr_, std::in_place);
+ }
+public:
+ // [expected.void.assign], assignment
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected& __rhs) noexcept(
@@ -1095,13 +1093,11 @@ class expected<_Tp, _Err> {
{
if (__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
- std::construct_at(std::addressof(__repr_.__union_.__unex_), __rhs.__repr_.__union_.__unex_);
- __repr_.__has_val_ = false;
+ __reinit_expected(std::unexpect, __rhs.__repr_.__union_.__unex_);
}
} else {
if (__rhs.__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- __repr_.__has_val_ = true;
+ __reinit_expected(std::in_place);
} else {
__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
@@ -1117,13 +1113,11 @@ class expected<_Tp, _Err> {
{
if (__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
- std::construct_at(std::addressof(__repr_.__union_.__unex_), std::move(__rhs.__repr_.__union_.__unex_));
- __repr_.__has_val_ = false;
+ __reinit_expected(std::unexpect, std::move(__rhs.__repr_.__union_.__unex_));
}
} else {
if (__rhs.__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- __repr_.__has_val_ = true;
+ __reinit_expected(std::in_place);
} else {
__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
@@ -1135,8 +1129,7 @@ class expected<_Tp, _Err> {
requires(is_constructible_v<_Err, const _OtherErr&> && is_assignable_v<_Err&, const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
if (__repr_.__has_val_) {
- std::construct_at(std::addressof(__repr_.__union_.__unex_), __un.error());
- __repr_.__has_val_ = false;
+ __reinit_expected(std::unexpect, __un.error());
} else {
__repr_.__union_.__unex_ = __un.error();
}
@@ -1147,8 +1140,7 @@ class expected<_Tp, _Err> {
requires(is_constructible_v<_Err, _OtherErr> && is_assignable_v<_Err&, _OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
if (__repr_.__has_val_) {
- std::construct_at(std::addressof(__repr_.__union_.__unex_), std::move(__un.error()));
- __repr_.__has_val_ = false;
+ __reinit_expected(std::unexpect, std::move(__un.error()));
} else {
__repr_.__union_.__unex_ = std::move(__un.error());
}
@@ -1157,8 +1149,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr void emplace() noexcept {
if (!__repr_.__has_val_) {
- std::destroy_at(std::addressof(__repr_.__union_.__unex_));
- __repr_.__has_val_ = true;
+ __reinit_expected(std::in_place);
}
}
@@ -1167,12 +1158,11 @@ class expected<_Tp, _Err> {
swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>&& is_nothrow_swappable_v<_Err>)
requires(is_swappable_v<_Err> && is_move_constructible_v<_Err>)
{
- auto __swap_val_unex_impl = [&](expected& __with_val, expected& __with_err) {
- std::construct_at(
- std::addressof(__with_val.__repr_.__union_.__unex_), std::move(__with_err.__repr_.__union_.__unex_));
- std::destroy_at(std::addressof(__with_err.__repr_.__union_.__unex_));
- __with_val.__repr_.__has_val_ = false;
- __with_err.__repr_.__has_val_ = true;
+ auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
+ // May throw, but will re-engage `__with_val` in that case.
+ __with_val.__reinit_expected(std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ // Will not throw.
+ __with_err.__reinit_expected(std::in_place);
};
if (__repr_.__has_val_) {
@@ -1516,7 +1506,7 @@ class expected<_Tp, _Err> {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // the expected's destructor handles this
+ // the __expected_repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
__empty_t __empty_;
@@ -1555,7 +1545,7 @@ class expected<_Tp, _Err> {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // the expected's destructor handles this
+ // the __expected_repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(!is_trivially_destructible_v<_ErrorType>)
{}
@@ -1564,7 +1554,56 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- __expected_repr<__union_t<_Err>> __repr_;
+ struct __expected_repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::in_place_t) : __union_(), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _Args&&... __args)
+ : __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ if (!__has_val_) {
+ std::destroy_at(std::addressof(__union_.__unex_));
+ }
+ }
+
+ private:
+ template <class, class>
+ friend class expected;
+
+ [[no_unique_address]] __union_t<_Err> __union_;
+ [[no_unique_address]] bool __has_val_;
+ };
+
+ __expected_repr __repr_;
};
_LIBCPP_END_NAMESPACE_STD
>From eb5172b7d968fb884decfe46a05965378c537785 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 11:40:48 +0200
Subject: [PATCH 08/55] remove unused 'expected<void>' constructor
---
libcxx/include/__expected/expected.h | 6 ------
1 file changed, 6 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index a2417d4802a079..ac61807676b64f 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -1051,12 +1051,6 @@ class expected<_Tp, _Err> {
: __repr_(std::unexpect, __il, std::forward<_Args>(__args)...) {}
private:
- template <class _Func>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(__expected_construct_in_place_from_invoke_tag, _Func&& __f)
- : __repr_(std::in_place) {
- std::invoke(std::forward<_Func>(__f));
- }
-
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
>From 589554aeaafea57af2b4eaf6e7b219b87dfb5856 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 11:48:59 +0200
Subject: [PATCH 09/55] remove unused datasizeof include
---
libcxx/include/__expected/expected.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index ac61807676b64f..ac20983c828d49 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -18,7 +18,6 @@
#include <__memory/addressof.h>
#include <__memory/construct_at.h>
#include <__type_traits/conjunction.h>
-#include <__type_traits/datasizeof.h>
#include <__type_traits/disjunction.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_assignable.h>
>From ccea6f00503bf9e1b8ca33bb5b22503cd903db94 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:29:09 +0200
Subject: [PATCH 10/55] rename 'std::in_place_t' to 'in_place_t'
Co-authored-by: philnik777 <nikolasklauser at berlin.de>
---
libcxx/include/__expected/expected.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index ac20983c828d49..9a6dae442856f2 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -813,7 +813,7 @@ class expected {
template <class _ValueType, class _ErrorType>
union __union_t {
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::in_place_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
: __val_(std::forward<_Args>(__args)...) {}
template <class... _Args>
>From 2eb62a10b32c41ab9cf6ba57100fd487d75cd2a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:32:27 +0200
Subject: [PATCH 11/55] std::in_place -> in_place
---
libcxx/include/__expected/expected.h | 59 ++++++++++++++--------------
1 file changed, 29 insertions(+), 30 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 9a6dae442856f2..5ae0f637f71263 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -113,7 +113,7 @@ class expected {
// [expected.object.ctor], constructors
_LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept(is_nothrow_default_constructible_v<_Tp>) // strengthened
requires is_default_constructible_v<_Tp>
- : __repr_(std::in_place) {}
+ : __repr_(in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -192,7 +192,7 @@ class expected {
(!is_same_v<remove_cv_t<_Tp>, bool> || !__is_std_expected<remove_cvref_t<_Up>>::value))
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp>)
expected(_Up&& __u) noexcept(is_nothrow_constructible_v<_Tp, _Up>) // strengthened
- : __repr_(std::in_place, std::forward<_Up>(__u)) {}
+ : __repr_(in_place, std::forward<_Up>(__u)) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
@@ -210,13 +210,13 @@ class expected {
requires is_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, _Args...>) // strengthened
- : __repr_(std::in_place, std::forward<_Args>(__args)...) {}
+ : __repr_(in_place, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(std::in_place, __il, std::forward<_Args>(__args)...) {}
+ : __repr_(in_place, __il, std::forward<_Args>(__args)...) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
@@ -271,10 +271,10 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
} else if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(
+ __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(
__repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(
+ __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(
__repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
} else {
__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
@@ -292,10 +292,10 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
} else if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(
+ __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(
__repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(
+ __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(
__repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
} else {
__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
@@ -313,7 +313,7 @@ class expected {
if (__repr_.__has_val_) {
__repr_.__union_.__val_ = std::forward<_Up>(__v);
} else {
- __reinit_expected<std::in_place_t, std::unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
+ __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
}
return *this;
}
@@ -333,7 +333,7 @@ class expected {
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
+ __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
} else {
__repr_.__union_.__unex_ = __un.error();
}
@@ -344,7 +344,7 @@ class expected {
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, std::in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
+ __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
} else {
__repr_.__union_.__unex_ = std::move(__un.error());
}
@@ -355,7 +355,7 @@ class expected {
requires is_nothrow_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
std::destroy_at(&__repr_);
- std::construct_at(&__repr_, std::in_place, std::forward<_Args>(__args)...);
+ std::construct_at(&__repr_, in_place, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
@@ -363,7 +363,7 @@ class expected {
requires is_nothrow_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
std::destroy_at(&__repr_);
- std::construct_at(&__repr_, std::in_place, __il, std::forward<_Args>(__args)...);
+ std::construct_at(&__repr_, in_place, __il, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
@@ -383,7 +383,7 @@ class expected {
auto __trans = std::__make_exception_guard([&] {
std::construct_at(&__with_err.__repr_, std::unexpect, std::move(__tmp));
});
- std::construct_at(&__with_err.__repr_, std::in_place, std::move(__with_val.__repr_.__union_.__val_));
+ std::construct_at(&__with_err.__repr_, in_place, std::move(__with_val.__repr_.__union_.__val_));
__trans.__complete();
std::destroy_at(&__with_val.__repr_);
std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__tmp));
@@ -393,13 +393,12 @@ class expected {
"that it can be reverted to the previous state in case an exception is thrown during swap.");
_Tp __tmp(std::move(__with_val.__repr_.__union_.__val_));
std::destroy_at(&__with_val.__repr_);
- auto __trans = std::__make_exception_guard([&] {
- std::construct_at(&__with_val.__repr_, std::in_place, std::move(__tmp));
- });
+ auto __trans =
+ std::__make_exception_guard([&] { std::construct_at(&__with_val.__repr_, in_place, std::move(__tmp)); });
std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
__trans.__complete();
std::destroy_at(&__with_err.__repr_);
- std::construct_at(&__with_err.__repr_, std::in_place, std::move(__tmp));
+ std::construct_at(&__with_err.__repr_, in_place, std::move(__tmp));
}
};
@@ -860,7 +859,7 @@ class expected {
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = default;
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::in_place_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
: __val_(std::forward<_Args>(__args)...) {}
template <class... _Args>
@@ -902,7 +901,7 @@ class expected {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::in_place_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
@@ -989,7 +988,7 @@ class expected<_Tp, _Err> {
using rebind = expected<_Up, error_type>;
// [expected.void.ctor], constructors
- _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_(std::in_place) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_(in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -1035,7 +1034,7 @@ class expected<_Tp, _Err> {
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
: __repr_(std::unexpect, std::move(__unex.error())) {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_(std::in_place) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_(in_place) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
@@ -1065,15 +1064,15 @@ class expected<_Tp, _Err> {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(std::unexpect_t, _Args&&... __args) {
std::destroy_at(&__repr_);
- auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, std::in_place); });
+ auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, in_place); });
std::construct_at(&__repr_, std::unexpect, std::forward<_Args>(__args)...);
__trans.__complete();
}
// precondition: !has_value()
- _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(std::in_place_t) {
+ _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(in_place_t) {
std::destroy_at(&__repr_);
- std::construct_at(&__repr_, std::in_place);
+ std::construct_at(&__repr_, in_place);
}
public:
@@ -1090,7 +1089,7 @@ class expected<_Tp, _Err> {
}
} else {
if (__rhs.__repr_.__has_val_) {
- __reinit_expected(std::in_place);
+ __reinit_expected(in_place);
} else {
__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
@@ -1110,7 +1109,7 @@ class expected<_Tp, _Err> {
}
} else {
if (__rhs.__repr_.__has_val_) {
- __reinit_expected(std::in_place);
+ __reinit_expected(in_place);
} else {
__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
@@ -1142,7 +1141,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr void emplace() noexcept {
if (!__repr_.__has_val_) {
- __reinit_expected(std::in_place);
+ __reinit_expected(in_place);
}
}
@@ -1155,7 +1154,7 @@ class expected<_Tp, _Err> {
// May throw, but will re-engage `__with_val` in that case.
__with_val.__reinit_expected(std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
// Will not throw.
- __with_err.__reinit_expected(std::in_place);
+ __with_err.__reinit_expected(in_place);
};
if (__repr_.__has_val_) {
@@ -1550,7 +1549,7 @@ class expected<_Tp, _Err> {
struct __expected_repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::in_place_t) : __union_(), __has_val_(true) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t) : __union_(), __has_val_(true) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::unexpect_t __tag, _Args&&... __args)
>From 21eff0f0c31452482d90cbe0357da89edb033a9d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:33:55 +0200
Subject: [PATCH 12/55] std::unexpect -> unexpect
---
libcxx/include/__expected/expected.h | 67 +++++++++++++---------------
1 file changed, 32 insertions(+), 35 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 5ae0f637f71263..5f18ffeaad81f8 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -198,13 +198,13 @@ class expected {
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(std::unexpect, __unex.error()) {}
+ : __repr_(unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(std::unexpect, std::move(__unex.error())) {}
+ : __repr_(unexpect, std::move(__unex.error())) {}
template <class... _Args>
requires is_constructible_v<_Tp, _Args...>
@@ -222,13 +222,13 @@ class expected {
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_(std::unexpect, std::forward<_Args>(__args)...) {}
+ : __repr_(unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(std::unexpect, __il, std::forward<_Args>(__args)...) {}
+ : __repr_(unexpect, __il, std::forward<_Args>(__args)...) {}
// [expected.object.dtor], destructor
@@ -271,11 +271,9 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
} else if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(
- __repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(
- __repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
} else {
__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
@@ -292,10 +290,10 @@ class expected {
if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
__repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
} else if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
__repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
__repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
} else {
__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
@@ -313,7 +311,7 @@ class expected {
if (__repr_.__has_val_) {
__repr_.__union_.__val_ = std::forward<_Up>(__v);
} else {
- __reinit_expected<in_place_t, std::unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
}
return *this;
}
@@ -333,7 +331,7 @@ class expected {
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
} else {
__repr_.__union_.__unex_ = __un.error();
}
@@ -344,7 +342,7 @@ class expected {
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
if (__repr_.__has_val_) {
- __reinit_expected<std::unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
} else {
__repr_.__union_.__unex_ = std::move(__un.error());
}
@@ -380,13 +378,12 @@ class expected {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
_Err __tmp(std::move(__with_err.__repr_.__union_.__unex_));
std::destroy_at(&__with_err.__repr_);
- auto __trans = std::__make_exception_guard([&] {
- std::construct_at(&__with_err.__repr_, std::unexpect, std::move(__tmp));
- });
+ auto __trans =
+ std::__make_exception_guard([&] { std::construct_at(&__with_err.__repr_, unexpect, std::move(__tmp)); });
std::construct_at(&__with_err.__repr_, in_place, std::move(__with_val.__repr_.__union_.__val_));
__trans.__complete();
std::destroy_at(&__with_val.__repr_);
- std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__tmp));
+ std::construct_at(&__with_val.__repr_, unexpect, std::move(__tmp));
} else {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
@@ -395,7 +392,7 @@ class expected {
std::destroy_at(&__with_val.__repr_);
auto __trans =
std::__make_exception_guard([&] { std::construct_at(&__with_val.__repr_, in_place, std::move(__tmp)); });
- std::construct_at(&__with_val.__repr_, std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ std::construct_at(&__with_val.__repr_, unexpect, std::move(__with_err.__repr_.__union_.__unex_));
__trans.__complete();
std::destroy_at(&__with_err.__repr_);
std::construct_at(&__with_err.__repr_, in_place, std::move(__tmp));
@@ -816,7 +813,7 @@ class expected {
: __val_(std::forward<_Args>(__args)...) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::unexpect_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
: __unex_(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -863,7 +860,7 @@ class expected {
: __val_(std::forward<_Args>(__args)...) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::unexpect_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
: __unex_(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -905,7 +902,7 @@ class expected {
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::unexpect_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
@@ -1026,13 +1023,13 @@ class expected<_Tp, _Err> {
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(std::unexpect, __unex.error()) {}
+ : __repr_(unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(std::unexpect, std::move(__unex.error())) {}
+ : __repr_(unexpect, std::move(__unex.error())) {}
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_(in_place) {}
@@ -1040,13 +1037,13 @@ class expected<_Tp, _Err> {
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_(std::unexpect, std::forward<_Args>(__args)...) {}
+ : __repr_(unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(std::unexpect, __il, std::forward<_Args>(__args)...) {}
+ : __repr_(unexpect, __il, std::forward<_Args>(__args)...) {}
private:
template <class _Func, class... _Args>
@@ -1062,10 +1059,10 @@ class expected<_Tp, _Err> {
private:
// precondition: has_value()
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(std::unexpect_t, _Args&&... __args) {
+ _LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(unexpect_t, _Args&&... __args) {
std::destroy_at(&__repr_);
auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, in_place); });
- std::construct_at(&__repr_, std::unexpect, std::forward<_Args>(__args)...);
+ std::construct_at(&__repr_, unexpect, std::forward<_Args>(__args)...);
__trans.__complete();
}
@@ -1085,7 +1082,7 @@ class expected<_Tp, _Err> {
{
if (__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
- __reinit_expected(std::unexpect, __rhs.__repr_.__union_.__unex_);
+ __reinit_expected(unexpect, __rhs.__repr_.__union_.__unex_);
}
} else {
if (__rhs.__repr_.__has_val_) {
@@ -1105,7 +1102,7 @@ class expected<_Tp, _Err> {
{
if (__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
- __reinit_expected(std::unexpect, std::move(__rhs.__repr_.__union_.__unex_));
+ __reinit_expected(unexpect, std::move(__rhs.__repr_.__union_.__unex_));
}
} else {
if (__rhs.__repr_.__has_val_) {
@@ -1121,7 +1118,7 @@ class expected<_Tp, _Err> {
requires(is_constructible_v<_Err, const _OtherErr&> && is_assignable_v<_Err&, const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
if (__repr_.__has_val_) {
- __reinit_expected(std::unexpect, __un.error());
+ __reinit_expected(unexpect, __un.error());
} else {
__repr_.__union_.__unex_ = __un.error();
}
@@ -1132,7 +1129,7 @@ class expected<_Tp, _Err> {
requires(is_constructible_v<_Err, _OtherErr> && is_assignable_v<_Err&, _OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
if (__repr_.__has_val_) {
- __reinit_expected(std::unexpect, std::move(__un.error()));
+ __reinit_expected(unexpect, std::move(__un.error()));
} else {
__repr_.__union_.__unex_ = std::move(__un.error());
}
@@ -1152,7 +1149,7 @@ class expected<_Tp, _Err> {
{
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
// May throw, but will re-engage `__with_val` in that case.
- __with_val.__reinit_expected(std::unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ __with_val.__reinit_expected(unexpect, std::move(__with_err.__repr_.__union_.__unex_));
// Will not throw.
__with_err.__reinit_expected(in_place);
};
@@ -1478,7 +1475,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::unexpect_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
: __unex_(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -1517,7 +1514,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = default;
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(std::unexpect_t, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
: __unex_(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -1552,7 +1549,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t) : __union_(), __has_val_(true) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(std::unexpect_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
>From 94100c0a0fef693bbdbd988fecfe23567a9a2254 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:37:54 +0200
Subject: [PATCH 13/55] use _LIBCPP_NO_UNIQUE_ADDRESS
Co-authored-by: philnik777 <nikolasklauser at berlin.de>
---
libcxx/include/__expected/expected.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 5f18ffeaad81f8..409fcd995506d5 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -950,8 +950,8 @@ class expected {
template <class, class>
friend class expected;
- [[no_unique_address]] __union_t<_Tp, _Err> __union_;
- [[no_unique_address]] bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
__expected_repr __repr_;
>From 848960f04e807e5d09cd5a2bba171370ff69184b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:39:00 +0200
Subject: [PATCH 14/55] use _LIBCPP_NO_UNIQUE_ADDRESS
---
libcxx/include/__expected/expected.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 409fcd995506d5..19d7620405df45 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -1588,8 +1588,8 @@ class expected<_Tp, _Err> {
template <class, class>
friend class expected;
- [[no_unique_address]] __union_t<_Err> __union_;
- [[no_unique_address]] bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
__expected_repr __repr_;
>From ff611a22494663fba2e27bb8d86b6ff3013e3487 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 13:43:23 +0200
Subject: [PATCH 15/55] remove _LIBCPP_GCC_DIAGNOSTIC_IGNORED (should be
separate issue)
---
libcxx/include/__type_traits/datasizeof.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/libcxx/include/__type_traits/datasizeof.h b/libcxx/include/__type_traits/datasizeof.h
index 197403ea0429dd..3a8b1516010731 100644
--- a/libcxx/include/__type_traits/datasizeof.h
+++ b/libcxx/include/__type_traits/datasizeof.h
@@ -55,7 +55,6 @@ struct __libcpp_datasizeof {
// the use as an extension.
_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Winvalid-offsetof")
- _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Winvalid-offsetof")
static const size_t value = offsetof(_FirstPaddingByte<>, __first_padding_byte_);
_LIBCPP_DIAGNOSTIC_POP
#endif // __has_extension(datasizeof)
>From a5cc76c8de32eb678eaaa82a26e3c805af0bee65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 21 Oct 2023 14:10:41 +0200
Subject: [PATCH 16/55] rename __expected_repr to __repr
---
libcxx/include/__expected/expected.h | 72 ++++++++++++++--------------
1 file changed, 36 insertions(+), 36 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 19d7620405df45..7e7e5c93e240ad 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -838,7 +838,7 @@ class expected {
requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
= default;
- // the __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
_ValueType __val_;
@@ -885,7 +885,7 @@ class expected {
requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
= default;
- // the __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(!is_trivially_destructible_v<_ValueType> || !is_trivially_destructible_v<_ErrorType>)
{}
@@ -894,49 +894,49 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- struct __expected_repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+ struct __repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_in_place_from_invoke_tag __tag,
+ _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
+ _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _Args&&... __args)
: __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
{
if (__has_val_) {
@@ -954,7 +954,7 @@ class expected {
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
- __expected_repr __repr_;
+ __repr __repr_;
};
template <class _Tp, class _Err>
@@ -1495,7 +1495,7 @@ class expected<_Tp, _Err> {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // the __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
__empty_t __empty_;
@@ -1534,7 +1534,7 @@ class expected<_Tp, _Err> {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // the __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(!is_trivially_destructible_v<_ErrorType>)
{}
@@ -1543,40 +1543,40 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
};
- struct __expected_repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+ struct __repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t) : __union_(), __has_val_(true) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t) : __union_(), __has_val_(true) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
+ _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _Args&&... __args)
: __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(is_trivially_destructible_v<_Err>)
= default;
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(!is_trivially_destructible_v<_Err>)
{
if (!__has_val_) {
@@ -1592,7 +1592,7 @@ class expected<_Tp, _Err> {
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
- __expected_repr __repr_;
+ __repr __repr_;
};
_LIBCPP_END_NAMESPACE_STD
>From 66eb9f17b68e783f071ef4a02e6f2900c218146c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Tue, 24 Oct 2023 16:52:35 +0200
Subject: [PATCH 17/55] implement optimized layout for types without tail
padding
---
libcxx/include/__expected/expected.h | 1093 ++++++++++-------
.../no_unique_address.compile.pass.cpp | 22 +-
.../transform_error.mandates.verify.cpp | 1 +
.../no_unique_address.compile.pass.cpp | 19 +-
.../transform_error.mandates.verify.cpp | 2 +
5 files changed, 704 insertions(+), 433 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 7e7e5c93e240ad..299575119a6b96 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,8 +88,277 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
+template <class _Union, class _OtherUnion>
+_LIBCPP_HIDE_FROM_ABI constexpr _Union __make_expected_union(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return _Union(in_place, std::forward<_OtherUnion>(__other).__val_);
+ else
+ return _Union(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+}
+
+template <class _ValueType, class _ErrorType>
+union __expected_union_t {
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(in_place_t, _Args&&... __args)
+ : __val_(std::forward<_Args>(__args)...) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
+ std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
+ std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t()
+ requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
+ = default;
+
+ // __expected_repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t() {}
+
+ // XXX Why are those not [[no_unique_address]]?
+ _ValueType __val_;
+ _ErrorType __unex_;
+};
+
+// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
+// also guaranteed elision into a potentially-overlapping subobject is unsettled (and
+// it's not clear that it's implementable, given that the function is allowed to clobber
+// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
+template <class _ValueType, class _ErrorType>
+ requires(is_trivially_move_constructible_v<_ValueType> && is_trivially_move_constructible_v<_ErrorType>)
+union __expected_union_t<_ValueType, _ErrorType> {
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_union_t(const __expected_union_t&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_union_t& operator=(const __expected_union_t&) = default;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(in_place_t, _Args&&... __args)
+ : __val_(std::forward<_Args>(__args)...) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
+ std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
+ std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t()
+ requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
+ = default;
+
+ // __expected_repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t() {}
+
+ _LIBCPP_NO_UNIQUE_ADDRESS _ValueType __val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
+};
+
+template <class _Tp, class _Err, bool _StuffTail = false>
+struct __expected_repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _OtherUnion&& __other)
+ : __union_(__make_expected_union<__expected_union_t<_Tp, _Err>>(__has_val, std::forward<_OtherUnion>(__other))),
+ __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Tp> &&
+ is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
+ is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ {
+ std::destroy_at(&__union_);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ std::destroy_at(&__union_);
+ }
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args) {
+ std::construct_at(&__union_, in_place, std::forward<_Args>(__args)...);
+ __has_val_ = true;
+ }
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args) {
+ std::construct_at(&__union_, unexpect, std::forward<_Args>(__args)...);
+ __has_val_ = false;
+ }
+
+private:
+ template <class, class>
+ friend class expected;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ if (__has_val_) {
+ std::destroy_at(std::addressof(__union_.__val_));
+ } else {
+ std::destroy_at(std::addressof(__union_.__unex_));
+ }
+ }
+
+ __expected_union_t<_Tp, _Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+};
+
+template <class _Tp, class _Err>
+struct __expected_repr<_Tp, _Err, true> {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _OtherUnion&& __other)
+ : __union_(__make_expected_union<__expected_union_t<_Tp, _Err>>(__has_val, std::forward<_OtherUnion>(__other))),
+ __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
+ requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Tp> &&
+ is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
+ requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
+ is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ if (__has_val_) {
+ std::destroy_at(std::addressof(__union_.__val_));
+ } else {
+ std::destroy_at(std::addressof(__union_.__unex_));
+ }
+ }
+
+private:
+ template <class, class>
+ friend class expected;
+
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_union_t<_Tp, _Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+};
+
+template <class _Tp, class _Err>
+struct __expected_base {
+protected:
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
+ : __repr_(std::forward<_Args>(__args)...) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { __repr_.__destroy_union(); }
+
+ template <class _Tag, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
+ __repr_.__construct_union(__tag, std::forward<_Args>(__args)...);
+ }
+
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_repr<_Tp, _Err, false> __repr_;
+};
+
+template <class _Tp, class _Err>
+ requires(sizeof(__expected_repr<_Tp, _Err, true>) == sizeof(__expected_union_t<_Tp, _Err>))
+struct __expected_base<_Tp, _Err> {
+protected:
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
+ : __repr_(std::forward<_Args>(__args)...) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
+
+ template <class _Tag, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
+ std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
+ }
+
+ __expected_repr<_Tp, _Err, true> __repr_;
+};
+
template <class _Tp, class _Err>
-class expected {
+class expected : private __expected_base<_Tp, _Err> {
static_assert(!is_reference_v<_Tp> && !is_function_v<_Tp> && !is_same_v<remove_cv_t<_Tp>, in_place_t> &&
!is_same_v<remove_cv_t<_Tp>, unexpect_t> && !__is_std_unexpected<remove_cv_t<_Tp>>::value &&
__valid_std_unexpected<_Err>::value,
@@ -102,6 +371,8 @@ class expected {
template <class _Up, class _OtherErr>
friend class expected;
+ using __base = __expected_base<_Tp, _Err>;
+
public:
using value_type = _Tp;
using error_type = _Err;
@@ -113,7 +384,7 @@ class expected {
// [expected.object.ctor], constructors
_LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept(is_nothrow_default_constructible_v<_Tp>) // strengthened
requires is_default_constructible_v<_Tp>
- : __repr_(in_place) {}
+ : __base(in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -126,7 +397,7 @@ class expected {
is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
- : __repr_(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
+ : __base(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
@@ -137,7 +408,7 @@ class expected {
is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
- : __repr_(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
+ : __base(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
private:
template <class _Up, class _OtherErr, class _UfQual, class _OtherErrQual>
@@ -162,12 +433,12 @@ class expected {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_in_place_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __base(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
std::__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __base(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
public:
template <class _Up, class _OtherErr>
@@ -177,14 +448,14 @@ class expected {
expected(const expected<_Up, _OtherErr>& __other) noexcept(
is_nothrow_constructible_v<_Tp, const _Up&>&&
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
+ : __base(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
+ : __base(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
template <class _Up = _Tp>
requires(!is_same_v<remove_cvref_t<_Up>, in_place_t> && !is_same_v<expected, remove_cvref_t<_Up>> &&
@@ -192,43 +463,43 @@ class expected {
(!is_same_v<remove_cv_t<_Tp>, bool> || !__is_std_expected<remove_cvref_t<_Up>>::value))
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp>)
expected(_Up&& __u) noexcept(is_nothrow_constructible_v<_Tp, _Up>) // strengthened
- : __repr_(in_place, std::forward<_Up>(__u)) {}
+ : __base(in_place, std::forward<_Up>(__u)) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(unexpect, __unex.error()) {}
+ : __base(unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(unexpect, std::move(__unex.error())) {}
+ : __base(unexpect, std::move(__unex.error())) {}
template <class... _Args>
requires is_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, _Args...>) // strengthened
- : __repr_(in_place, std::forward<_Args>(__args)...) {}
+ : __base(in_place, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(in_place, __il, std::forward<_Args>(__args)...) {}
+ : __base(in_place, __il, std::forward<_Args>(__args)...) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_(unexpect, std::forward<_Args>(__args)...) {}
+ : __base(unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(unexpect, __il, std::forward<_Args>(__args)...) {}
+ : __base(unexpect, __il, std::forward<_Args>(__args)...) {}
// [expected.object.dtor], destructor
@@ -238,21 +509,21 @@ class expected {
template <class _Tag, class _OtherTag, class _T1, class _T2, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(_T2& __oldval, _Args&&... __args) {
if constexpr (is_nothrow_constructible_v<_T1, _Args...>) {
- std::destroy_at(&__repr_);
- std::construct_at(&__repr_, _Tag{}, std::forward<_Args>(__args)...);
+ this->__destroy();
+ this->__construct(_Tag{}, std::forward<_Args>(__args)...);
} else if constexpr (is_nothrow_move_constructible_v<_T1>) {
_T1 __tmp(std::forward<_Args>(__args)...);
- std::destroy_at(&__repr_);
- std::construct_at(&__repr_, _Tag{}, std::move(__tmp));
+ this->__destroy();
+ this->__construct(_Tag{}, std::move(__tmp));
} else {
static_assert(
is_nothrow_move_constructible_v<_T2>,
"To provide strong exception guarantee, T2 has to satisfy `is_nothrow_move_constructible_v` so that it can "
"be reverted to the previous state in case an exception is thrown during the assignment.");
_T2 __tmp(std::move(__oldval));
- std::destroy_at(&__repr_);
- auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, _OtherTag{}, std::move(__tmp)); });
- std::construct_at(&__repr_, _Tag{}, std::forward<_Args>(__args)...);
+ this->__destroy();
+ auto __trans = std::__make_exception_guard([&] { this->__construct(_OtherTag{}, std::move(__tmp)); });
+ this->__construct(_Tag{}, std::forward<_Args>(__args)...);
__trans.__complete();
}
}
@@ -268,14 +539,16 @@ class expected {
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
- __repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
- } else if (__repr_.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
+ if (this->__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
+ this->__repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
+ } else if (this->__repr_.__has_val_) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
+ this->__repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
} else if (__rhs.__repr_.__has_val_) {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
+ this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
} else {
- __repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
+ this->__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
return *this;
}
@@ -287,16 +560,16 @@ class expected {
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
- __repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
- } else if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
+ this->__repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
+ } else if (this->__repr_.__has_val_) {
__reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- __repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
+ this->__repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
} else if (__rhs.__repr_.__has_val_) {
__reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- __repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
+ this->__repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
} else {
- __repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
+ this->__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
return *this;
}
@@ -308,10 +581,10 @@ class expected {
(is_nothrow_constructible_v<_Tp, _Up> || is_nothrow_move_constructible_v<_Tp> ||
is_nothrow_move_constructible_v<_Err>))
{
- if (__repr_.__has_val_) {
- __repr_.__union_.__val_ = std::forward<_Up>(__v);
+ if (this->__repr_.__has_val_) {
+ this->__repr_.__union_.__val_ = std::forward<_Up>(__v);
} else {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(__repr_.__union_.__unex_, std::forward<_Up>(__v));
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(this->__repr_.__union_.__unex_, std::forward<_Up>(__v));
}
return *this;
}
@@ -330,10 +603,10 @@ class expected {
template <class _OtherErr>
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (__repr_.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, __un.error());
+ if (this->__repr_.__has_val_) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__union_.__val_, __un.error());
} else {
- __repr_.__union_.__unex_ = __un.error();
+ this->__repr_.__union_.__unex_ = __un.error();
}
return *this;
}
@@ -341,10 +614,10 @@ class expected {
template <class _OtherErr>
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (__repr_.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(__repr_.__union_.__val_, std::move(__un.error()));
+ if (this->__repr_.__has_val_) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__union_.__val_, std::move(__un.error()));
} else {
- __repr_.__union_.__unex_ = std::move(__un.error());
+ this->__repr_.__union_.__unex_ = std::move(__un.error());
}
return *this;
}
@@ -352,16 +625,16 @@ class expected {
template <class... _Args>
requires is_nothrow_constructible_v<_Tp, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
- std::destroy_at(&__repr_);
- std::construct_at(&__repr_, in_place, std::forward<_Args>(__args)...);
+ this->__destroy();
+ this->__construct(in_place, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
template <class _Up, class... _Args>
requires is_nothrow_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
- std::destroy_at(&__repr_);
- std::construct_at(&__repr_, in_place, __il, std::forward<_Args>(__args)...);
+ this->__destroy();
+ this->__construct(in_place, __il, std::forward<_Args>(__args)...);
return __repr_.__union_.__val_;
}
@@ -377,32 +650,30 @@ class expected {
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
_Err __tmp(std::move(__with_err.__repr_.__union_.__unex_));
- std::destroy_at(&__with_err.__repr_);
- auto __trans =
- std::__make_exception_guard([&] { std::construct_at(&__with_err.__repr_, unexpect, std::move(__tmp)); });
- std::construct_at(&__with_err.__repr_, in_place, std::move(__with_val.__repr_.__union_.__val_));
+ __with_err.__destroy();
+ auto __trans = std::__make_exception_guard([&] { __with_err.__construct(unexpect, std::move(__tmp)); });
+ __with_err.__construct(in_place, std::move(__with_val.__repr_.__union_.__val_));
__trans.__complete();
- std::destroy_at(&__with_val.__repr_);
- std::construct_at(&__with_val.__repr_, unexpect, std::move(__tmp));
+ __with_val.__destroy();
+ __with_val.__construct(unexpect, std::move(__tmp));
} else {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
"that it can be reverted to the previous state in case an exception is thrown during swap.");
_Tp __tmp(std::move(__with_val.__repr_.__union_.__val_));
- std::destroy_at(&__with_val.__repr_);
- auto __trans =
- std::__make_exception_guard([&] { std::construct_at(&__with_val.__repr_, in_place, std::move(__tmp)); });
- std::construct_at(&__with_val.__repr_, unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ __with_val.__destroy();
+ auto __trans = std::__make_exception_guard([&] { __with_val.__construct(in_place, std::move(__tmp)); });
+ __with_val.__construct(unexpect, std::move(__with_err.__repr_.__union_.__unex_));
__trans.__complete();
- std::destroy_at(&__with_err.__repr_);
- std::construct_at(&__with_err.__repr_, in_place, std::move(__tmp));
+ __with_err.__destroy();
+ __with_err.__construct(in_place, std::move(__tmp));
}
};
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
if (__rhs.__repr_.__has_val_) {
using std::swap;
- swap(__repr_.__union_.__val_, __rhs.__repr_.__union_.__val_);
+ swap(this->__repr_.__union_.__val_, __rhs.__repr_.__union_.__val_);
} else {
__swap_val_unex_impl(*this, __rhs);
}
@@ -411,7 +682,7 @@ class expected {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
+ swap(this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
}
}
}
@@ -425,114 +696,116 @@ class expected {
// [expected.object.obs], observers
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp* operator->() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(__repr_.__union_.__val_);
+ this->__repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator->() noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(__repr_.__union_.__val_);
+ this->__repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return __repr_.__union_.__val_;
+ this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return this->__repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return __repr_.__union_.__val_;
+ this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return this->__repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(__repr_.__union_.__val_);
+ this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(this->__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(__repr_.__union_.__val_);
+ this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(this->__repr_.__union_.__val_);
}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__has_val_; }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& value() const& {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!__repr_.__has_val_) {
+ if (!this->__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return __repr_.__union_.__val_;
+ return this->__repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!__repr_.__has_val_) {
+ if (!this->__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return __repr_.__union_.__val_;
+ return this->__repr_.__union_.__val_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& value() const&& {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!__repr_.__has_val_) {
+ if (!this->__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(__repr_.__union_.__val_);
+ return std::move(this->__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!__repr_.__has_val_) {
+ if (!this->__repr_.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(__repr_.__union_.__val_);
+ return std::move(this->__repr_.__union_.__val_);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return __repr_.__union_.__unex_;
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return __repr_.__union_.__unex_;
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__repr_.__union_.__unex_);
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__union_.__unex_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__repr_.__union_.__unex_);
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__union_.__unex_);
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) const& {
static_assert(is_copy_constructible_v<_Tp>, "value_type has to be copy constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return __repr_.__has_val_ ? __repr_.__union_.__val_ : static_cast<_Tp>(std::forward<_Up>(__v));
+ return this->__repr_.__has_val_ ? this->__repr_.__union_.__val_ : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
static_assert(is_move_constructible_v<_Tp>, "value_type has to be move constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return __repr_.__has_val_ ? std::move(__repr_.__union_.__val_) : static_cast<_Tp>(std::forward<_Up>(__v));
+ return this->__repr_.__has_val_
+ ? std::move(this->__repr_.__union_.__val_)
+ : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up = _Err>
@@ -562,7 +835,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
}
return _Up(unexpect, error());
}
@@ -575,7 +848,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
}
return _Up(unexpect, error());
}
@@ -589,7 +862,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
}
return _Up(unexpect, std::move(error()));
}
@@ -603,7 +876,7 @@ class expected {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
}
return _Up(unexpect, std::move(error()));
}
@@ -616,7 +889,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, __repr_.__union_.__val_);
+ return _Gp(in_place, this->__repr_.__union_.__val_);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -629,7 +902,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, __repr_.__union_.__val_);
+ return _Gp(in_place, this->__repr_.__union_.__val_);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -643,7 +916,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(__repr_.__union_.__val_));
+ return _Gp(in_place, std::move(this->__repr_.__union_.__val_));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -657,7 +930,7 @@ class expected {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(__repr_.__union_.__val_));
+ return _Gp(in_place, std::move(this->__repr_.__union_.__val_));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -671,9 +944,9 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __repr_.__union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__repr_.__union_.__val_);
} else {
- std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
+ std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
return expected<_Up, _Err>();
}
}
@@ -687,9 +960,9 @@ class expected {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), __repr_.__union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__repr_.__union_.__val_);
} else {
- std::invoke(std::forward<_Func>(__f), __repr_.__union_.__val_);
+ std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
return expected<_Up, _Err>();
}
}
@@ -705,9 +978,9 @@ class expected {
return expected<_Up, _Err>(
__expected_construct_in_place_from_invoke_tag{},
std::forward<_Func>(__f),
- std::move(__repr_.__union_.__val_));
+ std::move(this->__repr_.__union_.__val_));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
return expected<_Up, _Err>();
}
}
@@ -723,9 +996,9 @@ class expected {
return expected<_Up, _Err>(
__expected_construct_in_place_from_invoke_tag{},
std::forward<_Func>(__f),
- std::move(__repr_.__union_.__val_));
+ std::move(this->__repr_.__union_.__val_));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(__repr_.__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
return expected<_Up, _Err>();
}
}
@@ -737,7 +1010,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, __repr_.__union_.__val_);
+ return expected<_Tp, _Gp>(in_place, this->__repr_.__union_.__val_);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -749,7 +1022,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, __repr_.__union_.__val_);
+ return expected<_Tp, _Gp>(in_place, this->__repr_.__union_.__val_);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -761,7 +1034,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(__repr_.__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__union_.__val_));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -774,7 +1047,7 @@ class expected {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(__repr_.__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__union_.__val_));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -804,162 +1077,249 @@ class expected {
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __e) {
return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __e.error());
}
+};
+
+struct __expected_empty_t {};
+
+template <class _Union, class _OtherUnion>
+_LIBCPP_HIDE_FROM_ABI constexpr _Union __make_expected_void_union(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return _Union(in_place);
+ else
+ return _Union(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+}
+
+template <class _ErrorType>
+union __expected_void_union_t {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(in_place_t) : __empty_() {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(
+ __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
+ requires(is_trivially_destructible_v<_ErrorType>)
+ = default;
+
+ // __expected_repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t() {}
+
+ // XXX: Why are those not [[no_unique_address]]?
+ __expected_empty_t __empty_;
+ _ErrorType __unex_;
+};
+
+// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
+// also guaranteed elision into a potentially-overlapping subobject is unsettled (and
+// it's not clear that it's implementable, given that the function is allowed to clobber
+// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
+template <class _ErrorType>
+ requires is_trivially_move_constructible_v<_ErrorType>
+union __expected_void_union_t<_ErrorType> {
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_union_t(const __expected_void_union_t&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_union_t& operator=(const __expected_void_union_t&) = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(in_place_t) : __empty_() {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(
+ __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
+ requires(is_trivially_destructible_v<_ErrorType>)
+ = default;
+
+ // __expected_repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
+ requires(!is_trivially_destructible_v<_ErrorType>)
+ {}
+
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_empty_t __empty_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
+};
+
+template <class _Err, bool _StuffTail = false>
+struct __expected_void_repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr() = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(bool __has_val, _OtherUnion&& __other)
+ : __union_(
+ __make_expected_void_union<__expected_void_union_t<_Err>>(__has_val, std::forward<_OtherUnion>(__other))),
+ __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
+ requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&)
+ requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr& operator=(const __expected_void_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
+ requires(is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(is_trivially_destructible_v<_Err>)
+ {
+ std::destroy_at(&__union_);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ std::destroy_at(&__union_);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t) {
+ std::construct_at(&__union_, in_place);
+ __has_val_ = true;
+ }
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args) {
+ std::construct_at(&__union_, unexpect, std::forward<_Args>(__args)...);
+ __has_val_ = false;
+ }
private:
- template <class _ValueType, class _ErrorType>
- union __union_t {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
- : __val_(std::forward<_Args>(__args)...) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Union>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(bool __has_val, _Union&& __other) {
- if (__has_val)
- std::construct_at(std::addressof(__val_), std::forward<_Union>(__other).__val_);
- else
- std::construct_at(std::addressof(__unex_), std::forward<_Union>(__other).__unex_);
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
-
- _ValueType __val_;
- _ErrorType __unex_;
- };
-
- // use named union because [[no_unique_address]] cannot be applied to an unnamed union,
- // also guaranteed elision into a potentially-overlapping subobject is unsettled (and
- // it's not clear that it's implementable, given that the function is allowed to clobber
- // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
- template <class _ValueType, class _ErrorType>
- requires(is_trivially_move_constructible_v<_ValueType> && is_trivially_move_constructible_v<_ErrorType>)
- union __union_t<_ValueType, _ErrorType> {
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = default;
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
- : __val_(std::forward<_Args>(__args)...) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Union>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(bool __has_val, _Union&& __other) {
- if (__has_val)
- std::construct_at(std::addressof(__val_), std::forward<_Union>(__other).__val_);
- else
- std::construct_at(std::addressof(__unex_), std::forward<_Union>(__other).__unex_);
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(!is_trivially_destructible_v<_ValueType> || !is_trivially_destructible_v<_ErrorType>)
- {}
-
- _LIBCPP_NO_UNIQUE_ADDRESS _ValueType __val_;
- _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
- };
-
- struct __repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_in_place_from_invoke_tag __tag,
- _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
- _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _Args&&... __args)
- : __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
- requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
- is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
- requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
- is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
- requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__union_.__unex_));
- }
+ template <class, class>
+ friend class expected;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ if (!__has_val_) {
+ std::destroy_at(std::addressof(__union_.__unex_));
+ }
+ }
+
+ __expected_void_union_t<_Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+};
+
+template <class _Err>
+struct __expected_void_repr<_Err, true> {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr() = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(
+ std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(bool __has_val, _OtherUnion&& __other)
+ : __union_(
+ __make_expected_void_union<__expected_void_union_t<_Err>>(__has_val, std::forward<_OtherUnion>(__other))),
+ __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
+ requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&)
+ requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr& operator=(const __expected_void_repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
+ requires(is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ if (!__has_val_) {
+ std::destroy_at(std::addressof(__union_.__unex_));
}
+ }
- private:
- template <class, class>
- friend class expected;
+private:
+ template <class, class>
+ friend class expected;
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
- };
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_void_union_t<_Err> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+};
+
+template <class _Err>
+struct __expected_void_base {
+protected:
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
+ : __repr_(std::forward<_Args>(__args)...) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { __repr_.__destroy_union(); }
- __repr __repr_;
+ template <class _Tag, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
+ __repr_.__construct_union(__tag, std::forward<_Args>(__args)...);
+ }
+
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_void_repr<_Err, false> __repr_;
+};
+
+template <class _Err>
+ requires(sizeof(__expected_void_repr<_Err, true>) == sizeof(__expected_void_union_t<_Err>))
+struct __expected_void_base<_Err> {
+protected:
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
+ : __repr_(std::forward<_Args>(__args)...) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
+
+ template <class _Tag, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
+ std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
+ }
+
+ __expected_void_repr<_Err, true> __repr_;
};
template <class _Tp, class _Err>
requires is_void_v<_Tp>
-class expected<_Tp, _Err> {
+class expected<_Tp, _Err> : private __expected_void_base<_Err> {
static_assert(__valid_std_unexpected<_Err>::value,
"[expected.void.general] A program that instantiates expected<T, E> with a E that is not a "
"valid argument for unexpected<E> is ill-formed");
@@ -976,6 +1336,8 @@ class expected<_Tp, _Err> {
_Not<is_constructible<unexpected<_Err>, const expected<_Up, _OtherErr>&>>,
_Not<is_constructible<unexpected<_Err>, const expected<_Up, _OtherErr>>>>;
+ using __base = __expected_void_base<_Err>;
+
public:
using value_type = _Tp;
using error_type = _Err;
@@ -985,7 +1347,7 @@ class expected<_Tp, _Err> {
using rebind = expected<_Up, error_type>;
// [expected.void.ctor], constructors
- _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __repr_(in_place) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr expected() noexcept : __base(in_place) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
@@ -996,7 +1358,7 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __rhs) noexcept(
is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Err> && !is_trivially_copy_constructible_v<_Err>)
- : __repr_(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
+ : __base(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
@@ -1004,52 +1366,52 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Err> && !is_trivially_move_constructible_v<_Err>)
- : __repr_(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
+ : __base(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, const _OtherErr&>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __rhs) noexcept(
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
+ : __base(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __rhs) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
+ : __base(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>) expected(
const unexpected<_OtherErr>& __unex) noexcept(is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __repr_(unexpect, __unex.error()) {}
+ : __base(unexpect, __unex.error()) {}
template <class _OtherErr>
requires is_constructible_v<_Err, _OtherErr>
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(unexpected<_OtherErr>&& __unex) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __repr_(unexpect, std::move(__unex.error())) {}
+ : __base(unexpect, std::move(__unex.error())) {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __repr_(in_place) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(in_place_t) noexcept : __base(in_place) {}
template <class... _Args>
requires is_constructible_v<_Err, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, _Args...>) // strengthened
- : __repr_(unexpect, std::forward<_Args>(__args)...) {}
+ : __base(unexpect, std::forward<_Args>(__args)...) {}
template <class _Up, class... _Args>
requires is_constructible_v< _Err, initializer_list<_Up>&, _Args... >
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(unexpect_t, initializer_list<_Up> __il, _Args&&... __args) noexcept(
is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened
- : __repr_(unexpect, __il, std::forward<_Args>(__args)...) {}
+ : __base(unexpect, __il, std::forward<_Args>(__args)...) {}
private:
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit expected(
__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args)
- : __repr_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __base(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
public:
// [expected.void.dtor], destructor
@@ -1060,16 +1422,16 @@ class expected<_Tp, _Err> {
// precondition: has_value()
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(unexpect_t, _Args&&... __args) {
- std::destroy_at(&__repr_);
- auto __trans = std::__make_exception_guard([&] { std::construct_at(&__repr_, in_place); });
- std::construct_at(&__repr_, unexpect, std::forward<_Args>(__args)...);
+ this->__destroy();
+ auto __trans = std::__make_exception_guard([&] { this->__construct(in_place); });
+ this->__construct(unexpect, std::forward<_Args>(__args)...);
__trans.__complete();
}
// precondition: !has_value()
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(in_place_t) {
- std::destroy_at(&__repr_);
- std::construct_at(&__repr_, in_place);
+ this->__destroy();
+ this->__construct(in_place);
}
public:
@@ -1080,7 +1442,7 @@ class expected<_Tp, _Err> {
is_nothrow_copy_assignable_v<_Err>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Err> && is_copy_constructible_v<_Err>)
{
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
__reinit_expected(unexpect, __rhs.__repr_.__union_.__unex_);
}
@@ -1088,7 +1450,7 @@ class expected<_Tp, _Err> {
if (__rhs.__repr_.__has_val_) {
__reinit_expected(in_place);
} else {
- __repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
+ this->__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
}
}
return *this;
@@ -1100,7 +1462,7 @@ class expected<_Tp, _Err> {
operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)
{
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
__reinit_expected(unexpect, std::move(__rhs.__repr_.__union_.__unex_));
}
@@ -1108,7 +1470,7 @@ class expected<_Tp, _Err> {
if (__rhs.__repr_.__has_val_) {
__reinit_expected(in_place);
} else {
- __repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
+ this->__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
}
}
return *this;
@@ -1117,10 +1479,10 @@ class expected<_Tp, _Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, const _OtherErr&> && is_assignable_v<_Err&, const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
__reinit_expected(unexpect, __un.error());
} else {
- __repr_.__union_.__unex_ = __un.error();
+ this->__repr_.__union_.__unex_ = __un.error();
}
return *this;
}
@@ -1128,16 +1490,16 @@ class expected<_Tp, _Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, _OtherErr> && is_assignable_v<_Err&, _OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
__reinit_expected(unexpect, std::move(__un.error()));
} else {
- __repr_.__union_.__unex_ = std::move(__un.error());
+ this->__repr_.__union_.__unex_ = std::move(__un.error());
}
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr void emplace() noexcept {
- if (!__repr_.__has_val_) {
+ if (!this->__repr_.__has_val_) {
__reinit_expected(in_place);
}
}
@@ -1154,7 +1516,7 @@ class expected<_Tp, _Err> {
__with_err.__reinit_expected(in_place);
};
- if (__repr_.__has_val_) {
+ if (this->__repr_.__has_val_) {
if (!__rhs.__repr_.__has_val_) {
__swap_val_unex_impl(*this, __rhs);
}
@@ -1163,7 +1525,7 @@ class expected<_Tp, _Err> {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
+ swap(this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
}
}
}
@@ -1175,51 +1537,51 @@ class expected<_Tp, _Err> {
}
// [expected.void.obs], observers
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__has_val_; }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr void operator*() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- __repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() const& {
static_assert(is_copy_constructible_v<_Err>);
- if (!__repr_.__has_val_) {
- std::__throw_bad_expected_access<_Err>(__repr_.__union_.__unex_);
+ if (!this->__repr_.__has_val_) {
+ std::__throw_bad_expected_access<_Err>(this->__repr_.__union_.__unex_);
}
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() && {
static_assert(is_copy_constructible_v<_Err> && is_move_constructible_v<_Err>);
- if (!__repr_.__has_val_) {
- std::__throw_bad_expected_access<_Err>(std::move(__repr_.__union_.__unex_));
+ if (!this->__repr_.__has_val_) {
+ std::__throw_bad_expected_access<_Err>(std::move(this->__repr_.__union_.__unex_));
}
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return __repr_.__union_.__unex_;
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return __repr_.__union_.__unex_;
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__union_.__unex_;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__repr_.__union_.__unex_);
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__union_.__unex_);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(__repr_.__union_.__unex_);
+ !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__union_.__unex_);
}
template <class _Up = _Err>
@@ -1466,133 +1828,6 @@ class expected<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __y) {
return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __y.error());
}
-
-private:
- struct __empty_t {};
-
- template <class _ErrorType>
- union __union_t {
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Union>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(bool __has_val, _Union&& __other) {
- if (__has_val)
- std::construct_at(std::addressof(__empty_));
- else
- std::construct_at(std::addressof(__unex_), std::forward<_Union>(__other).__unex_);
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
-
- __empty_t __empty_;
- _ErrorType __unex_;
- };
-
- // use named union because [[no_unique_address]] cannot be applied to an unnamed union,
- // also guaranteed elision into a potentially-overlapping subobject is unsettled (and
- // it's not clear that it's implementable, given that the function is allowed to clobber
- // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
- template <class _ErrorType>
- requires is_trivially_move_constructible_v<_ErrorType>
- union __union_t<_ErrorType> {
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {}
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = default;
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
- __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Union>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(bool __has_val, _Union&& __other) {
- if (__has_val)
- std::construct_at(std::addressof(__empty_));
- else
- std::construct_at(std::addressof(__unex_), std::forward<_Union>(__other).__unex_);
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
- requires(!is_trivially_destructible_v<_ErrorType>)
- {}
-
- _LIBCPP_NO_UNIQUE_ADDRESS __empty_t __empty_;
- _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
- };
-
- struct __repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t) : __union_(), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
- _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _Args&&... __args)
- : __union_(__has_val, std::forward<_Args>(__args)...), __has_val_(__has_val) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
- requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
- requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
- requires(is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
- requires(!is_trivially_destructible_v<_Err>)
- {
- if (!__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
- }
- }
-
- private:
- template <class, class>
- friend class expected;
-
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
- };
-
- __repr __repr_;
};
_LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index 8eeec70ff0e424..a7ddd13e7930aa 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -13,6 +13,7 @@
// test [[no_unique_address]] is applied to the union
#include <expected>
+#include <optional>
#include <memory>
struct Empty {};
@@ -50,5 +51,22 @@ static_assert(sizeof(std::expected<Empty, BoolWithPadding>) ==
// In this case, there should be tail padding in the `expected` because `A`
// itself does _not_ have tail padding.
-// XXX
-// static_assert(sizeof(std::expected<A, A>) > std::__libcpp_datasizeof<std::expected<A, A>>::value);
+static_assert(sizeof(std::expected<A, A>) > std::__libcpp_datasizeof<std::expected<A, A>>::value);
+
+// Test with some real types.
+static_assert(sizeof(std::expected<std::optional<int>, int>) == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<std::optional<int>, int>>::value == 8);
+
+static_assert(sizeof(std::expected<int, std::optional<int>>) == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<int, std::optional<int>>>::value == 8);
+
+static_assert(sizeof(std::expected<int, int>) == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<int, int>>::value == 5);
+
+// clang-format off
+static_assert(std::__libcpp_datasizeof<int>::value == 4);
+static_assert(std::__libcpp_datasizeof<std::expected<int, int>>::value == 5);
+static_assert(std::__libcpp_datasizeof<std::expected<std::expected<int, int>, int>>::value == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<std::expected<std::expected<int, int>, int>, int>>::value == 9);
+static_assert(std::__libcpp_datasizeof<std::expected<std::expected<std::expected<std::expected<int, int>, int>, int>, int>>::value == 12);
+// clang-format on
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 82024a068f00d1..14c27c6286eb05 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -52,6 +52,7 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}[expected.object.general] A program that instantiates the definition of template expected<T, E> for {{.*}} is ill-formed.}}
+ // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index 2129aa7b2405c7..fe4ef4f1e0e238 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -13,6 +13,7 @@
// test [[no_unique_address]] is applied to the union
#include <expected>
+#include <optional>
#include <memory>
struct Empty {};
@@ -44,5 +45,19 @@ static_assert(sizeof(std::expected<void, BoolWithPadding>) ==
// In this case, there should be tail padding in the `expected` because `A`
// itself does _not_ have tail padding.
-// XXX
-// static_assert(sizeof(std::expected<void, A>) > std::__libcpp_datasizeof<std::expected<void, A>>::value);
+static_assert(sizeof(std::expected<void, A>) > std::__libcpp_datasizeof<std::expected<void, A>>::value);
+
+// Test with some real types.
+static_assert(sizeof(std::expected<void, std::optional<int>>) == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<void, std::optional<int>>>::value == 8);
+
+static_assert(sizeof(std::expected<void, int>) == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<void, int>>::value == 5);
+
+// clang-format off
+static_assert(std::__libcpp_datasizeof<int>::value == 4);
+static_assert(std::__libcpp_datasizeof<std::expected<void, int>>::value == 5);
+static_assert(std::__libcpp_datasizeof<std::expected<void, std::expected<void, int>>>::value == 8);
+static_assert(std::__libcpp_datasizeof<std::expected<void, std::expected<void, std::expected<void, int>>>>::value == 9);
+static_assert(std::__libcpp_datasizeof<std::expected<void, std::expected<void, std::expected<void, std::expected<void, int>>>>>::value == 12);
+// clang-format on
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
index 0f2fb581ccd705..bc179b627a9a27 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
@@ -52,6 +52,8 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}A program that instantiates expected<T, E> with a E that is not a valid argument for unexpected<E> is ill-formed}}
+ // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
+ // expected-error-re@*:* {{call to deleted constructor of {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
>From 025c59cace3911cce10a70156bce93de59ed04a0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Tue, 24 Oct 2023 20:09:26 +0200
Subject: [PATCH 18/55] try to make guaranteed copy elision work with GCC
Seems to be related to
<https://github.com/itanium-cxx-abi/cxx-abi/issues/107>
---
libcxx/include/__expected/expected.h | 88 +++++++++++++++++-----------
1 file changed, 54 insertions(+), 34 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 299575119a6b96..d58fa49aa81c22 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,14 +88,6 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-template <class _Union, class _OtherUnion>
-_LIBCPP_HIDE_FROM_ABI constexpr _Union __make_expected_union(bool __has_val, _OtherUnion&& __other) {
- if (__has_val)
- return _Union(in_place, std::forward<_OtherUnion>(__other).__val_);
- else
- return _Union(unexpect, std::forward<_OtherUnion>(__other).__unex_);
-}
-
template <class _ValueType, class _ErrorType>
union __expected_union_t {
template <class... _Args>
@@ -191,8 +183,7 @@ struct __expected_repr {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(__make_expected_union<__expected_union_t<_Tp, _Err>>(__has_val, std::forward<_OtherUnion>(__other))),
- __has_val_(__has_val) {}
+ : __union_(__make_union(__has_val, std::forward<_OtherUnion>(__other))), __has_val_(__has_val) {}
_LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
@@ -256,6 +247,15 @@ struct __expected_repr {
}
}
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __expected_union_t<_Tp, _Err>
+ __make_union(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return __expected_union_t<_Tp, _Err>(in_place, std::forward<_OtherUnion>(__other).__val_);
+ else
+ return __expected_union_t<_Tp, _Err>(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ }
+
__expected_union_t<_Tp, _Err> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
@@ -282,11 +282,6 @@ struct __expected_repr<_Tp, _Err, true> {
std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(__make_expected_union<__expected_union_t<_Tp, _Err>>(__has_val, std::forward<_OtherUnion>(__other))),
- __has_val_(__has_val) {}
-
_LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Tp> &&
@@ -347,6 +342,10 @@ struct __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
: __repr_(std::forward<_Args>(__args)...) {}
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
+ : __repr_(__make_repr(__has_val, std::forward<_OtherUnion>(__other))) {}
+
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
template <class _Tag, class... _Args>
@@ -354,7 +353,19 @@ struct __expected_base<_Tp, _Err> {
std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
}
- __expected_repr<_Tp, _Err, true> __repr_;
+private:
+ using __repr = __expected_repr<_Tp, _Err, true>;
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return __repr(in_place, std::forward<_OtherUnion>(__other).__val_);
+ else
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ }
+
+protected:
+ __repr __repr_;
};
template <class _Tp, class _Err>
@@ -1081,14 +1092,6 @@ class expected : private __expected_base<_Tp, _Err> {
struct __expected_empty_t {};
-template <class _Union, class _OtherUnion>
-_LIBCPP_HIDE_FROM_ABI constexpr _Union __make_expected_void_union(bool __has_val, _OtherUnion&& __other) {
- if (__has_val)
- return _Union(in_place);
- else
- return _Union(unexpect, std::forward<_OtherUnion>(__other).__unex_);
-}
-
template <class _ErrorType>
union __expected_void_union_t {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(in_place_t) : __empty_() {}
@@ -1165,9 +1168,7 @@ struct __expected_void_repr {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(
- __make_expected_void_union<__expected_void_union_t<_Err>>(__has_val, std::forward<_OtherUnion>(__other))),
- __has_val_(__has_val) {}
+ : __union_(__make_union(__has_val, std::forward<_OtherUnion>(__other))), __has_val_(__has_val) {}
_LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
@@ -1226,6 +1227,15 @@ struct __expected_void_repr {
}
}
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __expected_void_union_t<_Err>
+ __make_union(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return __expected_void_union_t<_Err>(in_place);
+ else
+ return __expected_void_union_t<_Err>(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ }
+
__expected_void_union_t<_Err> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
@@ -1245,12 +1255,6 @@ struct __expected_void_repr<_Err, true> {
std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
: __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(
- __make_expected_void_union<__expected_void_union_t<_Err>>(__has_val, std::forward<_OtherUnion>(__other))),
- __has_val_(__has_val) {}
-
_LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
@@ -1307,6 +1311,10 @@ struct __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
: __repr_(std::forward<_Args>(__args)...) {}
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(bool __has_val, _OtherUnion&& __other)
+ : __repr_(__make_repr(__has_val, std::forward<_OtherUnion>(__other))) {}
+
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
template <class _Tag, class... _Args>
@@ -1314,7 +1322,19 @@ struct __expected_void_base<_Err> {
std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
}
- __expected_void_repr<_Err, true> __repr_;
+private:
+ using __repr = __expected_void_repr<_Err, true>;
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other) {
+ if (__has_val)
+ return __repr(in_place);
+ else
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ }
+
+protected:
+ __repr __repr_;
};
template <class _Tp, class _Err>
>From 21887f76812ecb316b82b3a30e89fc9ed6bec455 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Tue, 24 Oct 2023 22:47:14 +0200
Subject: [PATCH 19/55] add includes for datasizeof
---
.../expected.expected/no_unique_address.compile.pass.cpp | 1 +
.../expected/expected.void/no_unique_address.compile.pass.cpp | 1 +
2 files changed, 2 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index a7ddd13e7930aa..e316f7a0fc1b1e 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -12,6 +12,7 @@
// test [[no_unique_address]] is applied to the union
+#include <__type_traits/datasizeof.h>
#include <expected>
#include <optional>
#include <memory>
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index fe4ef4f1e0e238..e764dbd66acaa9 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -12,6 +12,7 @@
// test [[no_unique_address]] is applied to the union
+#include <__type_traits/datasizeof.h>
#include <expected>
#include <optional>
#include <memory>
>From 901c065cf496d0253b8675ba77c98607f807986b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 25 Oct 2023 19:23:18 +0200
Subject: [PATCH 20/55] use std::conditional for conditional
[[no_unique_address]]
---
libcxx/include/__expected/expected.h | 641 +++++++++---------
.../no_unique_address.compile.pass.cpp | 6 +-
.../transform_error.mandates.verify.cpp | 1 -
3 files changed, 307 insertions(+), 341 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index d58fa49aa81c22..55644648c35a2a 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,255 +88,204 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-template <class _ValueType, class _ErrorType>
-union __expected_union_t {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(in_place_t, _Args&&... __args)
- : __val_(std::forward<_Args>(__args)...) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
- std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
- std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t()
- requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __expected_repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t() {}
-
- // XXX Why are those not [[no_unique_address]]?
- _ValueType __val_;
- _ErrorType __unex_;
-};
-
-// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
-// also guaranteed elision into a potentially-overlapping subobject is unsettled (and
-// it's not clear that it's implementable, given that the function is allowed to clobber
-// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
-template <class _ValueType, class _ErrorType>
- requires(is_trivially_move_constructible_v<_ValueType> && is_trivially_move_constructible_v<_ErrorType>)
-union __expected_union_t<_ValueType, _ErrorType> {
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_union_t(const __expected_union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_union_t& operator=(const __expected_union_t&) = default;
+template <class _Tp>
+concept __expected_union_member_no_unique_address = is_nothrow_move_constructible_v<_Tp>;
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(in_place_t, _Args&&... __args)
- : __val_(std::forward<_Args>(__args)...) {}
+struct __expected_wrap_invoke_tag {};
+template <class _Tp>
+struct __expected_wrap_unique {
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_unique(_Args&&... __args)
+ : __v(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
- std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_unique(
+ __expected_wrap_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_union_t(
- std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t()
- requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __expected_repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_union_t() {}
-
- _LIBCPP_NO_UNIQUE_ADDRESS _ValueType __val_;
- _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
+ _Tp __v;
};
-template <class _Tp, class _Err, bool _StuffTail = false>
-struct __expected_repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(__make_union(__has_val, std::forward<_OtherUnion>(__other))), __has_val_(__has_val) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
- requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Tp> &&
- is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
- requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
- is_trivially_move_constructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
- requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- __destroy_union_member();
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
- {
- std::destroy_at(&__union_);
- }
-
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- __destroy_union_member();
- std::destroy_at(&__union_);
- }
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args) {
- std::construct_at(&__union_, in_place, std::forward<_Args>(__args)...);
- __has_val_ = true;
- }
-
+template <class _Tp>
+struct __expected_wrap_no_unique {
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args) {
- std::construct_at(&__union_, unexpect, std::forward<_Args>(__args)...);
- __has_val_ = false;
- }
-
-private:
- template <class, class>
- friend class expected;
-
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__union_.__unex_));
- }
- }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_no_unique(_Args&&... __args)
+ : __v(std::forward<_Args>(__args)...) {}
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI static constexpr __expected_union_t<_Tp, _Err>
- __make_union(bool __has_val, _OtherUnion&& __other) {
- if (__has_val)
- return __expected_union_t<_Tp, _Err>(in_place, std::forward<_OtherUnion>(__other).__val_);
- else
- return __expected_union_t<_Tp, _Err>(unexpect, std::forward<_OtherUnion>(__other).__unex_);
- }
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_no_unique(
+ __expected_wrap_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
- __expected_union_t<_Tp, _Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Tp __v;
};
-template <class _Tp, class _Err>
-struct __expected_repr<_Tp, _Err, true> {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr() = delete;
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(in_place_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_in_place_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(const __expected_repr&)
- requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Tp> &&
- is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr(__expected_repr&&)
- requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
- is_trivially_move_constructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_repr& operator=(const __expected_repr&) = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
- requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_repr()
- requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
- {
- if (__has_val_) {
- std::destroy_at(std::addressof(__union_.__val_));
- } else {
- std::destroy_at(std::addressof(__union_.__unex_));
- }
- }
-
-private:
- template <class, class>
- friend class expected;
-
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_union_t<_Tp, _Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+template <bool _NoUnique, class _Tp>
+struct __expected_conditional_no_unique_address {
+ using __type = std::conditional<_NoUnique, __expected_wrap_no_unique<_Tp>, __expected_wrap_unique<_Tp>>::type;
};
template <class _Tp, class _Err>
struct __expected_base {
-protected:
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
- : __repr_(std::forward<_Args>(__args)...) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { __repr_.__destroy_union(); }
+private:
+ // use named union because [[no_unique_address]] cannot be applied to an unnamed union,
+ // also guaranteed elision into a potentially-overlapping subobject is unsettled (and
+ // it's not clear that it's implementable, given that the function is allowed to clobber
+ // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
+ union __union_t {
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = delete;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
+ : __val_(std::forward<_Args>(__args)...) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
+ std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __val_(__expected_wrap_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
+ std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(__expected_wrap_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ = default;
+
+ // __repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
+
+ _LIBCPP_NO_UNIQUE_ADDRESS
+ __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Tp>, _Tp>::__type __val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Err>,
+ _Err>::__type __unex_;
+ };
+
+ _LIBCPP_HIDE_FROM_ABI static constexpr bool __can_stuff_tail() {
+ struct __x {
+ private:
+ _LIBCPP_NO_UNIQUE_ADDRESS __union_t __union;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val;
+ };
+ return sizeof(__x) == sizeof(__union_t);
+ }
+
+ struct __repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_in_place_from_invoke_tag __tag,
+ _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
+ _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
+ requires(!__can_stuff_tail())
+ : __union_(__expected_wrap_invoke_tag{},
+ [&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
+ __has_val_(__has_val) {}
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
+ requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
+ is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
+ requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
+ is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
+ requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
+ = default;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!__can_stuff_tail() && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
+ {
+ std::destroy_at(&__union_.__v);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!__can_stuff_tail() && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
+ {
+ __destroy_union_member();
+ std::destroy_at(&__union_.__v);
+ }
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args)
+ requires(!__can_stuff_tail())
+ {
+ std::construct_at(&__union_.__v, in_place, std::forward<_Args>(__args)...);
+ __has_val_ = true;
+ }
+
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
+ requires(!__can_stuff_tail())
+ {
+ std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
+ __has_val_ = false;
+ }
+
+ private:
+ template <class, class>
+ friend class expected;
+
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
+ requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
+ {
+ if (__has_val_) {
+ std::destroy_at(std::addressof(__union_.__v.__val_));
+ } else {
+ std::destroy_at(std::addressof(__union_.__v.__unex_));
+ }
+ }
- template <class _Tag, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- __repr_.__construct_union(__tag, std::forward<_Args>(__args)...);
- }
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
+ requires(!__can_stuff_tail())
+ {
+ if (__has_val)
+ return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
+ else
+ return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ }
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_repr<_Tp, _Err, false> __repr_;
-};
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail(), __union_t>::__type __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ };
-template <class _Tp, class _Err>
- requires(sizeof(__expected_repr<_Tp, _Err, true>) == sizeof(__expected_union_t<_Tp, _Err>))
-struct __expected_base<_Tp, _Err> {
protected:
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
@@ -344,28 +293,38 @@ struct __expected_base<_Tp, _Err> {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
- : __repr_(__make_repr(__has_val, std::forward<_OtherUnion>(__other))) {}
+ requires(__can_stuff_tail())
+ : __repr_(__expected_wrap_invoke_tag{},
+ [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
+ if constexpr (__can_stuff_tail())
+ std::destroy_at(&__repr_.__v);
+ else
+ __repr_.__v.__destroy_union();
+ }
template <class _Tag, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
+ if constexpr (__can_stuff_tail())
+ std::construct_at(&__repr_.__v, __tag, std::forward<_Args>(__args)...);
+ else
+ __repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
}
private:
- using __repr = __expected_repr<_Tp, _Err, true>;
-
template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other) {
+ _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
+ requires(__can_stuff_tail())
+ {
if (__has_val)
- return __repr(in_place, std::forward<_OtherUnion>(__other).__val_);
+ return __repr(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
else
- return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
}
protected:
- __repr __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail(), __repr>::__type __repr_;
};
template <class _Tp, class _Err>
@@ -408,7 +367,7 @@ class expected : private __expected_base<_Tp, _Err> {
is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
- : __base(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
+ : __base(__other.__repr_.__v.__has_val_, __other.__repr_.__v.__union_.__v) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
@@ -419,7 +378,7 @@ class expected : private __expected_base<_Tp, _Err> {
is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
- : __base(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
+ : __base(__other.__repr_.__v.__has_val_, std::move(__other.__repr_.__v.__union_.__v)) {}
private:
template <class _Up, class _OtherErr, class _UfQual, class _OtherErrQual>
@@ -459,14 +418,14 @@ class expected : private __expected_base<_Tp, _Err> {
expected(const expected<_Up, _OtherErr>& __other) noexcept(
is_nothrow_constructible_v<_Tp, const _Up&>&&
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __base(__other.__repr_.__has_val_, __other.__repr_.__union_) {}
+ : __base(__other.__repr_.__v.__has_val_, __other.__repr_.__v.__union_.__v) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __base(__other.__repr_.__has_val_, std::move(__other.__repr_.__union_)) {}
+ : __base(__other.__repr_.__v.__has_val_, std::move(__other.__repr_.__v.__union_.__v)) {}
template <class _Up = _Tp>
requires(!is_same_v<remove_cvref_t<_Up>, in_place_t> && !is_same_v<expected, remove_cvref_t<_Up>> &&
@@ -550,16 +509,16 @@ class expected : private __expected_base<_Tp, _Err> {
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
- this->__repr_.__union_.__val_ = __rhs.__repr_.__union_.__val_;
- } else if (this->__repr_.__has_val_) {
+ if (this->__repr_.__v.__has_val_ && __rhs.__repr_.__v.__has_val_) {
+ this->__repr_.__v.__union_.__v.__val_.__v = __rhs.__repr_.__v.__union_.__v.__val_.__v;
+ } else if (this->__repr_.__v.__has_val_) {
__reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- this->__repr_.__union_.__val_, __rhs.__repr_.__union_.__unex_);
- } else if (__rhs.__repr_.__has_val_) {
+ this->__repr_.__v.__union_.__v.__val_.__v, __rhs.__repr_.__v.__union_.__v.__unex_.__v);
+ } else if (__rhs.__repr_.__v.__has_val_) {
__reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__val_);
+ this->__repr_.__v.__union_.__v.__unex_.__v, __rhs.__repr_.__v.__union_.__v.__val_.__v);
} else {
- this->__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
+ this->__repr_.__v.__union_.__v.__unex_.__v = __rhs.__repr_.__v.__union_.__v.__unex_.__v;
}
return *this;
}
@@ -571,16 +530,16 @@ class expected : private __expected_base<_Tp, _Err> {
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__has_val_ && __rhs.__repr_.__has_val_) {
- this->__repr_.__union_.__val_ = std::move(__rhs.__repr_.__union_.__val_);
- } else if (this->__repr_.__has_val_) {
+ if (this->__repr_.__v.__has_val_ && __rhs.__repr_.__v.__has_val_) {
+ this->__repr_.__v.__union_.__v.__val_.__v = std::move(__rhs.__repr_.__v.__union_.__v.__val_.__v);
+ } else if (this->__repr_.__v.__has_val_) {
__reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- this->__repr_.__union_.__val_, std::move(__rhs.__repr_.__union_.__unex_));
- } else if (__rhs.__repr_.__has_val_) {
+ this->__repr_.__v.__union_.__v.__val_.__v, std::move(__rhs.__repr_.__v.__union_.__v.__unex_.__v));
+ } else if (__rhs.__repr_.__v.__has_val_) {
__reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- this->__repr_.__union_.__unex_, std::move(__rhs.__repr_.__union_.__val_));
+ this->__repr_.__v.__union_.__v.__unex_.__v, std::move(__rhs.__repr_.__v.__union_.__v.__val_.__v));
} else {
- this->__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
+ this->__repr_.__v.__union_.__v.__unex_.__v = std::move(__rhs.__repr_.__v.__union_.__v.__unex_.__v);
}
return *this;
}
@@ -592,10 +551,11 @@ class expected : private __expected_base<_Tp, _Err> {
(is_nothrow_constructible_v<_Tp, _Up> || is_nothrow_move_constructible_v<_Tp> ||
is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__has_val_) {
- this->__repr_.__union_.__val_ = std::forward<_Up>(__v);
+ if (this->__repr_.__v.__has_val_) {
+ this->__repr_.__v.__union_.__v.__val_.__v = std::forward<_Up>(__v);
} else {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(this->__repr_.__union_.__unex_, std::forward<_Up>(__v));
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
+ this->__repr_.__v.__union_.__v.__unex_.__v, std::forward<_Up>(__v));
}
return *this;
}
@@ -614,10 +574,10 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _OtherErr>
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (this->__repr_.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__union_.__val_, __un.error());
+ if (this->__repr_.__v.__has_val_) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__v.__union_.__v.__val_.__v, __un.error());
} else {
- this->__repr_.__union_.__unex_ = __un.error();
+ this->__repr_.__v.__union_.__v.__unex_.__v = __un.error();
}
return *this;
}
@@ -625,10 +585,11 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _OtherErr>
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (this->__repr_.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__union_.__val_, std::move(__un.error()));
+ if (this->__repr_.__v.__has_val_) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
+ this->__repr_.__v.__union_.__v.__val_.__v, std::move(__un.error()));
} else {
- this->__repr_.__union_.__unex_ = std::move(__un.error());
+ this->__repr_.__v.__union_.__v.__unex_.__v = std::move(__un.error());
}
return *this;
}
@@ -638,7 +599,7 @@ class expected : private __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
this->__destroy();
this->__construct(in_place, std::forward<_Args>(__args)...);
- return __repr_.__union_.__val_;
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
template <class _Up, class... _Args>
@@ -646,7 +607,7 @@ class expected : private __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
this->__destroy();
this->__construct(in_place, __il, std::forward<_Args>(__args)...);
- return __repr_.__union_.__val_;
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
public:
@@ -660,10 +621,10 @@ class expected : private __expected_base<_Tp, _Err> {
{
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
- _Err __tmp(std::move(__with_err.__repr_.__union_.__unex_));
+ _Err __tmp(std::move(__with_err.__repr_.__v.__union_.__v.__unex_.__v));
__with_err.__destroy();
auto __trans = std::__make_exception_guard([&] { __with_err.__construct(unexpect, std::move(__tmp)); });
- __with_err.__construct(in_place, std::move(__with_val.__repr_.__union_.__val_));
+ __with_err.__construct(in_place, std::move(__with_val.__repr_.__v.__union_.__v.__val_.__v));
__trans.__complete();
__with_val.__destroy();
__with_val.__construct(unexpect, std::move(__tmp));
@@ -671,29 +632,29 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
"that it can be reverted to the previous state in case an exception is thrown during swap.");
- _Tp __tmp(std::move(__with_val.__repr_.__union_.__val_));
+ _Tp __tmp(std::move(__with_val.__repr_.__v.__union_.__v.__val_.__v));
__with_val.__destroy();
auto __trans = std::__make_exception_guard([&] { __with_val.__construct(in_place, std::move(__tmp)); });
- __with_val.__construct(unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ __with_val.__construct(unexpect, std::move(__with_err.__repr_.__v.__union_.__v.__unex_.__v));
__trans.__complete();
__with_err.__destroy();
__with_err.__construct(in_place, std::move(__tmp));
}
};
- if (this->__repr_.__has_val_) {
- if (__rhs.__repr_.__has_val_) {
+ if (this->__repr_.__v.__has_val_) {
+ if (__rhs.__repr_.__v.__has_val_) {
using std::swap;
- swap(this->__repr_.__union_.__val_, __rhs.__repr_.__union_.__val_);
+ swap(this->__repr_.__v.__union_.__v.__val_.__v, __rhs.__repr_.__v.__union_.__v.__val_.__v);
} else {
__swap_val_unex_impl(*this, __rhs);
}
} else {
- if (__rhs.__repr_.__has_val_) {
+ if (__rhs.__repr_.__v.__has_val_) {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
+ swap(this->__repr_.__v.__union_.__v.__unex_.__v, __rhs.__repr_.__v.__union_.__v.__unex_.__v);
}
}
}
@@ -707,115 +668,117 @@ class expected : private __expected_base<_Tp, _Err> {
// [expected.object.obs], observers
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp* operator->() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(this->__repr_.__union_.__val_);
+ this->__repr_.__v.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__repr_.__v.__union_.__v.__val_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator->() noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(this->__repr_.__union_.__val_);
+ this->__repr_.__v.__has_val_, "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__repr_.__v.__union_.__v.__val_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return this->__repr_.__union_.__val_;
+ this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return this->__repr_.__union_.__val_;
+ this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(this->__repr_.__union_.__val_);
+ this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(this->__repr_.__union_.__val_);
+ this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
+ return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__v.__has_val_; }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__v.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& value() const& {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!this->__repr_.__has_val_) {
+ if (!this->__repr_.__v.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return this->__repr_.__union_.__val_;
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!this->__repr_.__has_val_) {
+ if (!this->__repr_.__v.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return this->__repr_.__union_.__val_;
+ return this->__repr_.__v.__union_.__v.__val_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& value() const&& {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!this->__repr_.__has_val_) {
+ if (!this->__repr_.__v.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(this->__repr_.__union_.__val_);
+ return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!this->__repr_.__has_val_) {
+ if (!this->__repr_.__v.__has_val_) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(this->__repr_.__union_.__val_);
+ return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__union_.__unex_;
+ !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__v.__union_.__v.__unex_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__union_.__unex_;
+ !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
+ return this->__repr_.__v.__union_.__v.__unex_.__v;
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__union_.__unex_);
+ !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__v.__union_.__v.__unex_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__union_.__unex_);
+ !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
+ return std::move(this->__repr_.__v.__union_.__v.__unex_.__v);
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) const& {
static_assert(is_copy_constructible_v<_Tp>, "value_type has to be copy constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return this->__repr_.__has_val_ ? this->__repr_.__union_.__val_ : static_cast<_Tp>(std::forward<_Up>(__v));
+ return this->__repr_.__v.__has_val_
+ ? this->__repr_.__v.__union_.__v.__val_.__v
+ : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
static_assert(is_move_constructible_v<_Tp>, "value_type has to be move constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return this->__repr_.__has_val_
- ? std::move(this->__repr_.__union_.__val_)
+ return this->__repr_.__v.__has_val_
+ ? std::move(this->__repr_.__v.__union_.__v.__val_.__v)
: static_cast<_Tp>(std::forward<_Up>(__v));
}
@@ -846,7 +809,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
}
return _Up(unexpect, error());
}
@@ -859,7 +822,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ return std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
}
return _Up(unexpect, error());
}
@@ -873,7 +836,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return _Up(unexpect, std::move(error()));
}
@@ -887,7 +850,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return _Up(unexpect, std::move(error()));
}
@@ -900,7 +863,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, this->__repr_.__union_.__val_);
+ return _Gp(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -913,7 +876,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, this->__repr_.__union_.__val_);
+ return _Gp(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -927,7 +890,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(this->__repr_.__union_.__val_));
+ return _Gp(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -941,7 +904,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(this->__repr_.__union_.__val_));
+ return _Gp(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -955,9 +918,11 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{},
+ std::forward<_Func>(__f),
+ this->__repr_.__v.__union_.__v.__val_.__v);
} else {
- std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
return expected<_Up, _Err>();
}
}
@@ -971,9 +936,11 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ __expected_construct_in_place_from_invoke_tag{},
+ std::forward<_Func>(__f),
+ this->__repr_.__v.__union_.__v.__val_.__v);
} else {
- std::invoke(std::forward<_Func>(__f), this->__repr_.__union_.__val_);
+ std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
return expected<_Up, _Err>();
}
}
@@ -989,9 +956,9 @@ class expected : private __expected_base<_Tp, _Err> {
return expected<_Up, _Err>(
__expected_construct_in_place_from_invoke_tag{},
std::forward<_Func>(__f),
- std::move(this->__repr_.__union_.__val_));
+ std::move(this->__repr_.__v.__union_.__v.__val_.__v));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
return expected<_Up, _Err>();
}
}
@@ -1007,9 +974,9 @@ class expected : private __expected_base<_Tp, _Err> {
return expected<_Up, _Err>(
__expected_construct_in_place_from_invoke_tag{},
std::forward<_Func>(__f),
- std::move(this->__repr_.__union_.__val_));
+ std::move(this->__repr_.__v.__union_.__v.__val_.__v));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__union_.__val_));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
return expected<_Up, _Err>();
}
}
@@ -1021,7 +988,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, this->__repr_.__union_.__val_);
+ return expected<_Tp, _Gp>(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -1033,7 +1000,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, this->__repr_.__union_.__val_);
+ return expected<_Tp, _Gp>(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -1045,7 +1012,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -1058,7 +1025,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__union_.__val_));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -1068,25 +1035,25 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _T2, class _E2>
requires(!is_void_v<_T2>)
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const expected<_T2, _E2>& __y) {
- if (__x.__repr_.__has_val_ != __y.__repr_.__has_val_) {
+ if (__x.__repr_.__v.__has_val_ != __y.__repr_.__v.__has_val_) {
return false;
} else {
- if (__x.__repr_.__has_val_) {
- return __x.__repr_.__union_.__val_ == __y.__repr_.__union_.__val_;
+ if (__x.__repr_.__v.__has_val_) {
+ return __x.__repr_.__v.__union_.__v.__val_.__v == __y.__repr_.__v.__union_.__v.__val_.__v;
} else {
- return __x.__repr_.__union_.__unex_ == __y.__repr_.__union_.__unex_;
+ return __x.__repr_.__v.__union_.__v.__unex_.__v == __y.__repr_.__v.__union_.__v.__unex_.__v;
}
}
}
template <class _T2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const _T2& __v) {
- return __x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__val_ == __v);
+ return __x.__repr_.__v.__has_val_ && static_cast<bool>(__x.__repr_.__v.__union_.__v.__val_.__v == __v);
}
template <class _E2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __e) {
- return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __e.error());
+ return !__x.__repr_.__v.__has_val_ && static_cast<bool>(__x.__repr_.__v.__union_.__v.__unex_.__v == __e.error());
}
};
@@ -1109,7 +1076,7 @@ union __expected_void_union_t {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t() {}
// XXX: Why are those not [[no_unique_address]]?
@@ -1142,7 +1109,7 @@ union __expected_void_union_t<_ErrorType> {
requires(is_trivially_destructible_v<_ErrorType>)
= default;
- // __expected_repr's destructor handles this
+ // __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
requires(!is_trivially_destructible_v<_ErrorType>)
{}
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index e316f7a0fc1b1e..4d523d1ad69500 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -38,11 +38,11 @@ struct BoolWithPadding {
static_assert(sizeof(std::expected<Empty, Empty>) == sizeof(bool));
static_assert(sizeof(std::expected<Empty, A>) == 2 * sizeof(int) + alignof(std::expected<Empty, A>));
-static_assert(sizeof(std::expected<Empty, B>) == sizeof(B) + alignof(std::expected<Empty, B>));
+static_assert(sizeof(std::expected<Empty, B>) == sizeof(B));
static_assert(sizeof(std::expected<A, Empty>) == 2 * sizeof(int) + alignof(std::expected<A, Empty>));
static_assert(sizeof(std::expected<A, A>) == 2 * sizeof(int) + alignof(std::expected<A, A>));
-static_assert(sizeof(std::expected<B, Empty>) == sizeof(B) + alignof(std::expected<B, Empty>));
-static_assert(sizeof(std::expected<B, B>) == sizeof(B) + alignof(std::expected<B, B>));
+static_assert(sizeof(std::expected<B, Empty>) == sizeof(B));
+static_assert(sizeof(std::expected<B, B>) == sizeof(B));
// Check that `expected`'s datasize is large enough for the parameter type(s).
static_assert(sizeof(std::expected<BoolWithPadding, Empty>) ==
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 14c27c6286eb05..82024a068f00d1 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -52,7 +52,6 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}[expected.object.general] A program that instantiates the definition of template expected<T, E> for {{.*}} is ill-formed.}}
- // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
>From 285c342060a7254f28aa0034367598395ecab43c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 25 Oct 2023 19:39:46 +0200
Subject: [PATCH 21/55] slight refactoring
---
libcxx/include/__expected/expected.h | 81 +++++++++++++---------------
1 file changed, 36 insertions(+), 45 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 55644648c35a2a..d5d783290f80f8 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -91,44 +91,38 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
template <class _Tp>
concept __expected_union_member_no_unique_address = is_nothrow_move_constructible_v<_Tp>;
-struct __expected_wrap_invoke_tag {};
+struct __expected_invoke_tag {};
-template <class _Tp>
-struct __expected_wrap_unique {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_unique(_Args&&... __args)
- : __v(std::forward<_Args>(__args)...) {}
+template <bool _NoUnique, class _Tp>
+class __expected_conditional_no_unique_address {
+ struct __unique {
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __unique(_Args&&... __args) : __v(std::forward<_Args>(__args)...) {}
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_unique(
- __expected_wrap_invoke_tag, _Func&& __f, _Args&&... __args)
- : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __unique(__expected_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
- _Tp __v;
-};
+ _Tp __v;
+ };
-template <class _Tp>
-struct __expected_wrap_no_unique {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_no_unique(_Args&&... __args)
- : __v(std::forward<_Args>(__args)...) {}
+ struct __no_unique {
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __no_unique(_Args&&... __args) : __v(std::forward<_Args>(__args)...) {}
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_wrap_no_unique(
- __expected_wrap_invoke_tag, _Func&& __f, _Args&&... __args)
- : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __no_unique(__expected_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
- _LIBCPP_NO_UNIQUE_ADDRESS _Tp __v;
-};
+ _LIBCPP_NO_UNIQUE_ADDRESS _Tp __v;
+ };
-template <bool _NoUnique, class _Tp>
-struct __expected_conditional_no_unique_address {
- using __type = std::conditional<_NoUnique, __expected_wrap_no_unique<_Tp>, __expected_wrap_unique<_Tp>>::type;
+public:
+ using __type = std::conditional<_NoUnique, __no_unique, __unique>::type;
};
template <class _Tp, class _Err>
-struct __expected_base {
-private:
+class __expected_base {
// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
// also guaranteed elision into a potentially-overlapping subobject is unsettled (and
// it's not clear that it's implementable, given that the function is allowed to clobber
@@ -149,12 +143,12 @@ struct __expected_base {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(__expected_wrap_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __val_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(__expected_wrap_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __unex_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
@@ -202,7 +196,7 @@ struct __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
requires(!__can_stuff_tail())
- : __union_(__expected_wrap_invoke_tag{},
+ : __union_(__expected_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -286,6 +280,16 @@ struct __expected_base {
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
+ requires(__can_stuff_tail())
+ {
+ if (__has_val)
+ return __repr(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
+ else
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ }
+
protected:
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
@@ -294,8 +298,7 @@ struct __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
requires(__can_stuff_tail())
- : __repr_(__expected_wrap_invoke_tag{},
- [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
+ : __repr_(__expected_invoke_tag{}, [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
if constexpr (__can_stuff_tail())
@@ -312,18 +315,6 @@ struct __expected_base {
__repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
}
-private:
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail())
- {
- if (__has_val)
- return __repr(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
- else
- return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
- }
-
-protected:
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail(), __repr>::__type __repr_;
};
>From 8c2eb556a5c852d21c4fd85e8e3f39c6fca0d28a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 25 Oct 2023 20:10:11 +0200
Subject: [PATCH 22/55] more refactoring
---
libcxx/include/__expected/expected.h | 43 +++++++++++++++-------------
1 file changed, 23 insertions(+), 20 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index d5d783290f80f8..cac3b6aa94887d 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -121,6 +121,16 @@ class __expected_conditional_no_unique_address {
using __type = std::conditional<_NoUnique, __no_unique, __unique>::type;
};
+template <class _Union>
+_LIBCPP_HIDE_FROM_ABI constexpr bool __expected_can_stuff_tail() {
+ struct __x {
+ private:
+ _LIBCPP_NO_UNIQUE_ADDRESS _Union __union;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val;
+ };
+ return sizeof(__x) == sizeof(_Union);
+}
+
template <class _Tp, class _Err>
class __expected_base {
// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
@@ -163,14 +173,7 @@ class __expected_base {
_Err>::__type __unex_;
};
- _LIBCPP_HIDE_FROM_ABI static constexpr bool __can_stuff_tail() {
- struct __x {
- private:
- _LIBCPP_NO_UNIQUE_ADDRESS __union_t __union;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val;
- };
- return sizeof(__x) == sizeof(__union_t);
- }
+ static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
struct __repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
@@ -195,7 +198,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail())
+ requires(!__can_stuff_tail)
: __union_(__expected_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -224,13 +227,13 @@ class __expected_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail() && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
+ requires(!__can_stuff_tail && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
{
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail() && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
+ requires(!__can_stuff_tail && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
{
__destroy_union_member();
std::destroy_at(&__union_.__v);
@@ -238,7 +241,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args)
- requires(!__can_stuff_tail())
+ requires(!__can_stuff_tail)
{
std::construct_at(&__union_.__v, in_place, std::forward<_Args>(__args)...);
__has_val_ = true;
@@ -246,7 +249,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
- requires(!__can_stuff_tail())
+ requires(!__can_stuff_tail)
{
std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
__has_val_ = false;
@@ -268,7 +271,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail())
+ requires(!__can_stuff_tail)
{
if (__has_val)
return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
@@ -276,13 +279,13 @@ class __expected_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail(), __union_t>::__type __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail())
+ requires(__can_stuff_tail)
{
if (__has_val)
return __repr(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
@@ -297,11 +300,11 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail())
+ requires(__can_stuff_tail)
: __repr_(__expected_invoke_tag{}, [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
- if constexpr (__can_stuff_tail())
+ if constexpr (__can_stuff_tail)
std::destroy_at(&__repr_.__v);
else
__repr_.__v.__destroy_union();
@@ -309,13 +312,13 @@ class __expected_base {
template <class _Tag, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- if constexpr (__can_stuff_tail())
+ if constexpr (__can_stuff_tail)
std::construct_at(&__repr_.__v, __tag, std::forward<_Args>(__args)...);
else
__repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail(), __repr>::__type __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
};
template <class _Tp, class _Err>
>From 0fb34bfbe0242abbd11c47579535673aa11b5952 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 25 Oct 2023 21:00:34 +0200
Subject: [PATCH 23/55] refactor expected<void>
---
libcxx/include/__expected/expected.h | 642 ++++++++----------
.../no_unique_address.compile.pass.cpp | 2 +-
.../transform_error.mandates.verify.cpp | 2 +-
3 files changed, 285 insertions(+), 361 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index cac3b6aa94887d..f691a4f5a7390c 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -257,7 +257,7 @@ class __expected_base {
private:
template <class, class>
- friend class expected;
+ friend class __expected_base;
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>)
@@ -318,6 +318,15 @@ class __expected_base {
__repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
}
+ _LIBCPP_HIDE_FROM_ABI constexpr bool __has_val() const { return __repr_.__v.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& __union() { return __repr_.__v.__union_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const __union_t& __union() const { return __repr_.__v.__union_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Tp& __val() { return __repr_.__v.__union_.__v.__val_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& __val() const { return __repr_.__v.__union_.__v.__val_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_.__v; }
+
+private:
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
};
@@ -361,7 +370,7 @@ class expected : private __expected_base<_Tp, _Err> {
is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
- : __base(__other.__repr_.__v.__has_val_, __other.__repr_.__v.__union_.__v) {}
+ : __base(__other.__has_val(), __other.__union()) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Tp> &&
@@ -372,7 +381,7 @@ class expected : private __expected_base<_Tp, _Err> {
is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
- : __base(__other.__repr_.__v.__has_val_, std::move(__other.__repr_.__v.__union_.__v)) {}
+ : __base(__other.__has_val(), std::move(__other.__union())) {}
private:
template <class _Up, class _OtherErr, class _UfQual, class _OtherErrQual>
@@ -412,14 +421,14 @@ class expected : private __expected_base<_Tp, _Err> {
expected(const expected<_Up, _OtherErr>& __other) noexcept(
is_nothrow_constructible_v<_Tp, const _Up&>&&
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __base(__other.__repr_.__v.__has_val_, __other.__repr_.__v.__union_.__v) {}
+ : __base(__other.__has_val(), __other.__union()) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __base(__other.__repr_.__v.__has_val_, std::move(__other.__repr_.__v.__union_.__v)) {}
+ : __base(__other.__has_val(), std::move(__other.__union())) {}
template <class _Up = _Tp>
requires(!is_same_v<remove_cvref_t<_Up>, in_place_t> && !is_same_v<expected, remove_cvref_t<_Up>> &&
@@ -503,16 +512,14 @@ class expected : private __expected_base<_Tp, _Err> {
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__v.__has_val_ && __rhs.__repr_.__v.__has_val_) {
- this->__repr_.__v.__union_.__v.__val_.__v = __rhs.__repr_.__v.__union_.__v.__val_.__v;
- } else if (this->__repr_.__v.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- this->__repr_.__v.__union_.__v.__val_.__v, __rhs.__repr_.__v.__union_.__v.__unex_.__v);
- } else if (__rhs.__repr_.__v.__has_val_) {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- this->__repr_.__v.__union_.__v.__unex_.__v, __rhs.__repr_.__v.__union_.__v.__val_.__v);
+ if (this->__has_val() && __rhs.__has_val()) {
+ this->__val() = __rhs.__val();
+ } else if (this->__has_val()) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__val(), __rhs.__unex());
+ } else if (__rhs.__has_val()) {
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(this->__unex(), __rhs.__val());
} else {
- this->__repr_.__v.__union_.__v.__unex_.__v = __rhs.__repr_.__v.__union_.__v.__unex_.__v;
+ this->__unex() = __rhs.__unex();
}
return *this;
}
@@ -524,16 +531,14 @@ class expected : private __expected_base<_Tp, _Err> {
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__v.__has_val_ && __rhs.__repr_.__v.__has_val_) {
- this->__repr_.__v.__union_.__v.__val_.__v = std::move(__rhs.__repr_.__v.__union_.__v.__val_.__v);
- } else if (this->__repr_.__v.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- this->__repr_.__v.__union_.__v.__val_.__v, std::move(__rhs.__repr_.__v.__union_.__v.__unex_.__v));
- } else if (__rhs.__repr_.__v.__has_val_) {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- this->__repr_.__v.__union_.__v.__unex_.__v, std::move(__rhs.__repr_.__v.__union_.__v.__val_.__v));
+ if (this->__has_val() && __rhs.__has_val()) {
+ this->__val() = std::move(__rhs.__val());
+ } else if (this->__has_val()) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__val(), std::move(__rhs.__unex()));
+ } else if (__rhs.__has_val()) {
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(this->__unex(), std::move(__rhs.__val()));
} else {
- this->__repr_.__v.__union_.__v.__unex_.__v = std::move(__rhs.__repr_.__v.__union_.__v.__unex_.__v);
+ this->__unex() = std::move(__rhs.__unex());
}
return *this;
}
@@ -545,11 +550,10 @@ class expected : private __expected_base<_Tp, _Err> {
(is_nothrow_constructible_v<_Tp, _Up> || is_nothrow_move_constructible_v<_Tp> ||
is_nothrow_move_constructible_v<_Err>))
{
- if (this->__repr_.__v.__has_val_) {
- this->__repr_.__v.__union_.__v.__val_.__v = std::forward<_Up>(__v);
+ if (this->__has_val()) {
+ this->__val() = std::forward<_Up>(__v);
} else {
- __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(
- this->__repr_.__v.__union_.__v.__unex_.__v, std::forward<_Up>(__v));
+ __reinit_expected<in_place_t, unexpect_t, _Tp, _Err>(this->__unex(), std::forward<_Up>(__v));
}
return *this;
}
@@ -568,10 +572,10 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _OtherErr>
requires(__can_assign_from_unexpected<const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (this->__repr_.__v.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__repr_.__v.__union_.__v.__val_.__v, __un.error());
+ if (this->__has_val()) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__val(), __un.error());
} else {
- this->__repr_.__v.__union_.__v.__unex_.__v = __un.error();
+ this->__unex() = __un.error();
}
return *this;
}
@@ -579,11 +583,10 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _OtherErr>
requires(__can_assign_from_unexpected<_OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (this->__repr_.__v.__has_val_) {
- __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(
- this->__repr_.__v.__union_.__v.__val_.__v, std::move(__un.error()));
+ if (this->__has_val()) {
+ __reinit_expected<unexpect_t, in_place_t, _Err, _Tp>(this->__val(), std::move(__un.error()));
} else {
- this->__repr_.__v.__union_.__v.__unex_.__v = std::move(__un.error());
+ this->__unex() = std::move(__un.error());
}
return *this;
}
@@ -593,15 +596,15 @@ class expected : private __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(_Args&&... __args) noexcept {
this->__destroy();
this->__construct(in_place, std::forward<_Args>(__args)...);
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ return this->__val();
}
template <class _Up, class... _Args>
- requires is_nothrow_constructible_v< _Tp, initializer_list<_Up>&, _Args... >
+ requires is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) noexcept {
this->__destroy();
this->__construct(in_place, __il, std::forward<_Args>(__args)...);
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ return this->__val();
}
public:
@@ -615,10 +618,10 @@ class expected : private __expected_base<_Tp, _Err> {
{
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
if constexpr (is_nothrow_move_constructible_v<_Err>) {
- _Err __tmp(std::move(__with_err.__repr_.__v.__union_.__v.__unex_.__v));
+ _Err __tmp(std::move(__with_err.__unex()));
__with_err.__destroy();
auto __trans = std::__make_exception_guard([&] { __with_err.__construct(unexpect, std::move(__tmp)); });
- __with_err.__construct(in_place, std::move(__with_val.__repr_.__v.__union_.__v.__val_.__v));
+ __with_err.__construct(in_place, std::move(__with_val.__val()));
__trans.__complete();
__with_val.__destroy();
__with_val.__construct(unexpect, std::move(__tmp));
@@ -626,29 +629,29 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_nothrow_move_constructible_v<_Tp>,
"To provide strong exception guarantee, Tp has to satisfy `is_nothrow_move_constructible_v` so "
"that it can be reverted to the previous state in case an exception is thrown during swap.");
- _Tp __tmp(std::move(__with_val.__repr_.__v.__union_.__v.__val_.__v));
+ _Tp __tmp(std::move(__with_val.__val()));
__with_val.__destroy();
auto __trans = std::__make_exception_guard([&] { __with_val.__construct(in_place, std::move(__tmp)); });
- __with_val.__construct(unexpect, std::move(__with_err.__repr_.__v.__union_.__v.__unex_.__v));
+ __with_val.__construct(unexpect, std::move(__with_err.__unex()));
__trans.__complete();
__with_err.__destroy();
__with_err.__construct(in_place, std::move(__tmp));
}
};
- if (this->__repr_.__v.__has_val_) {
- if (__rhs.__repr_.__v.__has_val_) {
+ if (this->__has_val()) {
+ if (__rhs.__has_val()) {
using std::swap;
- swap(this->__repr_.__v.__union_.__v.__val_.__v, __rhs.__repr_.__v.__union_.__v.__val_.__v);
+ swap(this->__val(), __rhs.__val());
} else {
__swap_val_unex_impl(*this, __rhs);
}
} else {
- if (__rhs.__repr_.__v.__has_val_) {
+ if (__rhs.__has_val()) {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(this->__repr_.__v.__union_.__v.__unex_.__v, __rhs.__repr_.__v.__union_.__v.__unex_.__v);
+ swap(this->__unex(), __rhs.__unex());
}
}
}
@@ -662,118 +665,114 @@ class expected : private __expected_base<_Tp, _Err> {
// [expected.object.obs], observers
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp* operator->() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(this->__repr_.__v.__union_.__v.__val_.__v);
+ this->__has_val(), "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__val());
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator->() noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator-> requires the expected to contain a value");
- return std::addressof(this->__repr_.__v.__union_.__v.__val_.__v);
+ this->__has_val(), "expected::operator-> requires the expected to contain a value");
+ return std::addressof(this->__val());
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ this->__has_val(), "expected::operator* requires the expected to contain a value");
+ return this->__val();
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ this->__has_val(), "expected::operator* requires the expected to contain a value");
+ return this->__val();
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
+ this->__has_val(), "expected::operator* requires the expected to contain a value");
+ return std::move(this->__val());
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__v.__has_val_, "expected::operator* requires the expected to contain a value");
- return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
+ this->__has_val(), "expected::operator* requires the expected to contain a value");
+ return std::move(this->__val());
}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__v.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__has_val(); }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__v.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__has_val(); }
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp& value() const& {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!this->__repr_.__v.__has_val_) {
+ if (!this->__has_val()) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ return this->__val();
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & {
static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible");
- if (!this->__repr_.__v.__has_val_) {
+ if (!this->__has_val()) {
std::__throw_bad_expected_access<_Err>(std::as_const(error()));
}
- return this->__repr_.__v.__union_.__v.__val_.__v;
+ return this->__val();
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& value() const&& {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!this->__repr_.__v.__has_val_) {
+ if (!this->__has_val()) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
+ return std::move(this->__val());
}
_LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && {
static_assert(is_copy_constructible_v<_Err> && is_constructible_v<_Err, decltype(std::move(error()))>,
"error_type has to be both copy constructible and constructible from decltype(std::move(error()))");
- if (!this->__repr_.__v.__has_val_) {
+ if (!this->__has_val()) {
std::__throw_bad_expected_access<_Err>(std::move(error()));
}
- return std::move(this->__repr_.__v.__union_.__v.__val_.__v);
+ return std::move(this->__val());
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__v.__union_.__v.__unex_.__v;
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return this->__unex();
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__v.__union_.__v.__unex_.__v;
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return this->__unex();
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__v.__union_.__v.__unex_.__v);
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return std::move(this->__unex());
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__v.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__v.__union_.__v.__unex_.__v);
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return std::move(this->__unex());
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) const& {
static_assert(is_copy_constructible_v<_Tp>, "value_type has to be copy constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return this->__repr_.__v.__has_val_
- ? this->__repr_.__v.__union_.__v.__val_.__v
- : static_cast<_Tp>(std::forward<_Up>(__v));
+ return this->__has_val() ? this->__val() : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
static_assert(is_move_constructible_v<_Tp>, "value_type has to be move constructible");
static_assert(is_convertible_v<_Up, _Tp>, "argument has to be convertible to value_type");
- return this->__repr_.__v.__has_val_
- ? std::move(this->__repr_.__v.__union_.__v.__val_.__v)
- : static_cast<_Tp>(std::forward<_Up>(__v));
+ return this->__has_val() ? std::move(this->__val()) : static_cast<_Tp>(std::forward<_Up>(__v));
}
template <class _Up = _Err>
@@ -803,7 +802,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
+ return std::invoke(std::forward<_Func>(__f), this->__val());
}
return _Up(unexpect, error());
}
@@ -816,7 +815,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(**this) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
+ return std::invoke(std::forward<_Func>(__f), this->__val());
}
return _Up(unexpect, error());
}
@@ -830,7 +829,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__val()));
}
return _Up(unexpect, std::move(error()));
}
@@ -844,7 +843,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Up::error_type, _Err>,
"The result of f(std::move(**this)) must have the same error_type as this expected");
if (has_value()) {
- return std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return std::invoke(std::forward<_Func>(__f), std::move(this->__val()));
}
return _Up(unexpect, std::move(error()));
}
@@ -857,7 +856,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
+ return _Gp(in_place, this->__val());
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -870,7 +869,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(error()) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
+ return _Gp(in_place, this->__val());
}
return std::invoke(std::forward<_Func>(__f), error());
}
@@ -884,7 +883,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return _Gp(in_place, std::move(this->__val()));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -898,7 +897,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(is_same_v<typename _Gp::value_type, _Tp>,
"The result of f(std::move(error())) must have the same value_type as this expected");
if (has_value()) {
- return _Gp(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return _Gp(in_place, std::move(this->__val()));
}
return std::invoke(std::forward<_Func>(__f), std::move(error()));
}
@@ -912,11 +911,9 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{},
- std::forward<_Func>(__f),
- this->__repr_.__v.__union_.__v.__val_.__v);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__val());
} else {
- std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
+ std::invoke(std::forward<_Func>(__f), this->__val());
return expected<_Up, _Err>();
}
}
@@ -930,11 +927,9 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{},
- std::forward<_Func>(__f),
- this->__repr_.__v.__union_.__v.__val_.__v);
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), this->__val());
} else {
- std::invoke(std::forward<_Func>(__f), this->__repr_.__v.__union_.__v.__val_.__v);
+ std::invoke(std::forward<_Func>(__f), this->__val());
return expected<_Up, _Err>();
}
}
@@ -948,11 +943,9 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{},
- std::forward<_Func>(__f),
- std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(this->__val()));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__val()));
return expected<_Up, _Err>();
}
}
@@ -966,11 +959,9 @@ class expected : private __expected_base<_Tp, _Err> {
}
if constexpr (!is_void_v<_Up>) {
return expected<_Up, _Err>(
- __expected_construct_in_place_from_invoke_tag{},
- std::forward<_Func>(__f),
- std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(this->__val()));
} else {
- std::invoke(std::forward<_Func>(__f), std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ std::invoke(std::forward<_Func>(__f), std::move(this->__val()));
return expected<_Up, _Err>();
}
}
@@ -982,7 +973,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
+ return expected<_Tp, _Gp>(in_place, this->__val());
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -994,7 +985,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(error()) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, this->__repr_.__v.__union_.__v.__val_.__v);
+ return expected<_Tp, _Gp>(in_place, this->__val());
}
return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error());
}
@@ -1006,7 +997,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__val()));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -1019,7 +1010,7 @@ class expected : private __expected_base<_Tp, _Err> {
static_assert(__valid_std_unexpected<_Gp>::value,
"The result of f(std::move(error())) must be a valid template argument for unexpected");
if (has_value()) {
- return expected<_Tp, _Gp>(in_place, std::move(this->__repr_.__v.__union_.__v.__val_.__v));
+ return expected<_Tp, _Gp>(in_place, std::move(this->__val()));
}
return expected<_Tp, _Gp>(
__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error()));
@@ -1029,244 +1020,173 @@ class expected : private __expected_base<_Tp, _Err> {
template <class _T2, class _E2>
requires(!is_void_v<_T2>)
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const expected<_T2, _E2>& __y) {
- if (__x.__repr_.__v.__has_val_ != __y.__repr_.__v.__has_val_) {
+ if (__x.__has_val() != __y.__has_val()) {
return false;
} else {
- if (__x.__repr_.__v.__has_val_) {
- return __x.__repr_.__v.__union_.__v.__val_.__v == __y.__repr_.__v.__union_.__v.__val_.__v;
+ if (__x.__has_val()) {
+ return __x.__val() == __y.__val();
} else {
- return __x.__repr_.__v.__union_.__v.__unex_.__v == __y.__repr_.__v.__union_.__v.__unex_.__v;
+ return __x.__unex() == __y.__unex();
}
}
}
template <class _T2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const _T2& __v) {
- return __x.__repr_.__v.__has_val_ && static_cast<bool>(__x.__repr_.__v.__union_.__v.__val_.__v == __v);
+ return __x.__has_val() && static_cast<bool>(__x.__val() == __v);
}
template <class _E2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __e) {
- return !__x.__repr_.__v.__has_val_ && static_cast<bool>(__x.__repr_.__v.__union_.__v.__unex_.__v == __e.error());
+ return !__x.__has_val() && static_cast<bool>(__x.__unex() == __e.error());
}
};
-struct __expected_empty_t {};
-
-template <class _ErrorType>
-union __expected_void_union_t {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(in_place_t) : __empty_() {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
-
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(
- __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
- requires(is_trivially_destructible_v<_ErrorType>)
- = default;
-
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t() {}
+template <class _Err>
+class __expected_void_base {
+ struct __empty_t {};
+ // use named union because [[no_unique_address]] cannot be applied to an unnamed union,
+ // also guaranteed elision into a potentially-overlapping subobject is unsettled (and
+ // it's not clear that it's implementable, given that the function is allowed to clobber
+ // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
+ union __union_t {
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = delete;
- // XXX: Why are those not [[no_unique_address]]?
- __expected_empty_t __empty_;
- _ErrorType __unex_;
-};
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t) : __empty_() {}
-// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
-// also guaranteed elision into a potentially-overlapping subobject is unsettled (and
-// it's not clear that it's implementable, given that the function is allowed to clobber
-// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
-template <class _ErrorType>
- requires is_trivially_move_constructible_v<_ErrorType>
-union __expected_void_union_t<_ErrorType> {
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_union_t(const __expected_void_union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_union_t& operator=(const __expected_void_union_t&) = default;
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(unexpect_t, _Args&&... __args)
+ : __unex_(std::forward<_Args>(__args)...) {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(in_place_t) : __empty_() {}
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
+ __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __unex_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(unexpect_t, _Args&&... __args)
- : __unex_(std::forward<_Args>(__args)...) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
+ requires(is_trivially_destructible_v<_Err>)
+ = default;
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_union_t(
- __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+ // __repr's destructor handles this
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
+ requires(!is_trivially_destructible_v<_Err>)
+ {}
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
- requires(is_trivially_destructible_v<_ErrorType>)
- = default;
+ _LIBCPP_NO_UNIQUE_ADDRESS __empty_t __empty_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Err>,
+ _Err>::__type __unex_;
+ };
- // __repr's destructor handles this
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_union_t()
- requires(!is_trivially_destructible_v<_ErrorType>)
- {}
+ static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_empty_t __empty_;
- _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_;
-};
+ struct __repr {
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
-template <class _Err, bool _StuffTail = false>
-struct __expected_void_repr {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr() = delete;
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
+ _Args&&... __args)
+ : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
+ requires(!__can_stuff_tail)
+ : __union_(__expected_invoke_tag{},
+ [&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
+ __has_val_(__has_val) {}
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(bool __has_val, _OtherUnion&& __other)
- : __union_(__make_union(__has_val, std::forward<_OtherUnion>(__other))), __has_val_(__has_val) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(const __repr&)
+ requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr(__repr&&)
+ requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
+ = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
- requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&)
- requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
- = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr& operator=(const __expected_void_repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
+ requires(is_trivially_destructible_v<_Err>)
+ = default;
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
- requires(is_trivially_destructible_v<_Err>)
- = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ }
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
- requires(!is_trivially_destructible_v<_Err>)
- {
- __destroy_union_member();
- }
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!__can_stuff_tail && is_trivially_destructible_v<_Err>)
+ {
+ std::destroy_at(&__union_.__v);
+ }
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(is_trivially_destructible_v<_Err>)
- {
- std::destroy_at(&__union_);
- }
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
+ requires(!__can_stuff_tail && !is_trivially_destructible_v<_Err>)
+ {
+ __destroy_union_member();
+ std::destroy_at(&__union_.__v);
+ }
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!is_trivially_destructible_v<_Err>)
- {
- __destroy_union_member();
- std::destroy_at(&__union_);
- }
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t)
+ requires(!__can_stuff_tail)
+ {
+ std::construct_at(&__union_.__v, in_place);
+ __has_val_ = true;
+ }
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t) {
- std::construct_at(&__union_, in_place);
- __has_val_ = true;
- }
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
+ requires(!__can_stuff_tail)
+ {
+ std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
+ __has_val_ = false;
+ }
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args) {
- std::construct_at(&__union_, unexpect, std::forward<_Args>(__args)...);
- __has_val_ = false;
- }
+ private:
+ template <class>
+ friend class __expected_void_base;
-private:
- template <class, class>
- friend class expected;
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
+ requires(!is_trivially_destructible_v<_Err>)
+ {
+ if (!__has_val_)
+ std::destroy_at(std::addressof(__union_.__v.__unex_));
+ }
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union_member()
- requires(!is_trivially_destructible_v<_Err>)
- {
- if (!__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
+ template <class _OtherUnion>
+ _LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
+ requires(!__can_stuff_tail)
+ {
+ if (__has_val)
+ return __union_t(in_place);
+ else
+ return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
}
- }
+
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ };
template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI static constexpr __expected_void_union_t<_Err>
- __make_union(bool __has_val, _OtherUnion&& __other) {
+ _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
+ requires(__can_stuff_tail)
+ {
if (__has_val)
- return __expected_void_union_t<_Err>(in_place);
+ return __repr(in_place);
else
- return __expected_void_union_t<_Err>(unexpect, std::forward<_OtherUnion>(__other).__unex_);
- }
-
- __expected_void_union_t<_Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
-};
-
-template <class _Err>
-struct __expected_void_repr<_Err, true> {
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr() = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_repr(
- std::__expected_construct_unexpected_from_invoke_tag __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(const __expected_void_repr&)
- requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
- = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&) = delete;
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr(__expected_void_repr&&)
- requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr __expected_void_repr& operator=(const __expected_void_repr&) = delete;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
- requires(is_trivially_destructible_v<_Err>)
- = default;
-
- _LIBCPP_HIDE_FROM_ABI constexpr ~__expected_void_repr()
- requires(!is_trivially_destructible_v<_Err>)
- {
- if (!__has_val_) {
- std::destroy_at(std::addressof(__union_.__unex_));
- }
- }
-
-private:
- template <class, class>
- friend class expected;
-
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_void_union_t<_Err> __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
-};
-
-template <class _Err>
-struct __expected_void_base {
-protected:
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
- : __repr_(std::forward<_Args>(__args)...) {}
-
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { __repr_.__destroy_union(); }
-
- template <class _Tag, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- __repr_.__construct_union(__tag, std::forward<_Args>(__args)...);
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_void_repr<_Err, false> __repr_;
-};
-
-template <class _Err>
- requires(sizeof(__expected_void_repr<_Err, true>) == sizeof(__expected_void_union_t<_Err>))
-struct __expected_void_base<_Err> {
protected:
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
@@ -1274,28 +1194,32 @@ struct __expected_void_base<_Err> {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(bool __has_val, _OtherUnion&& __other)
- : __repr_(__make_repr(__has_val, std::forward<_OtherUnion>(__other))) {}
+ requires(__can_stuff_tail)
+ : __repr_(__expected_invoke_tag{}, [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
- _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() { std::destroy_at(&__repr_); }
+ _LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
+ if constexpr (__can_stuff_tail)
+ std::destroy_at(&__repr_.__v);
+ else
+ __repr_.__v.__destroy_union();
+ }
template <class _Tag, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- std::construct_at(&__repr_, __tag, std::forward<_Args>(__args)...);
- }
-
-private:
- using __repr = __expected_void_repr<_Err, true>;
-
- template <class _OtherUnion>
- _LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other) {
- if (__has_val)
- return __repr(in_place);
+ if constexpr (__can_stuff_tail)
+ std::construct_at(&__repr_.__v, __tag, std::forward<_Args>(__args)...);
else
- return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
+ __repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
}
-protected:
- __repr __repr_;
+ _LIBCPP_HIDE_FROM_ABI constexpr bool __has_val() const { return __repr_.__v.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& __union() { return __repr_.__v.__union_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const __union_t& __union() const { return __repr_.__v.__union_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_.__v; }
+
+private:
+ _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
};
template <class _Tp, class _Err>
@@ -1339,7 +1263,7 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __rhs) noexcept(
is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Err> && !is_trivially_copy_constructible_v<_Err>)
- : __base(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
+ : __base(__rhs.__has_val(), __rhs.__union()) {}
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&&)
requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
@@ -1347,20 +1271,20 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Err> && !is_trivially_move_constructible_v<_Err>)
- : __base(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
+ : __base(__rhs.__has_val(), std::move(__rhs.__union())) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, const _OtherErr&>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __rhs) noexcept(
is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
- : __base(__rhs.__repr_.__has_val_, __rhs.__repr_.__union_) {}
+ : __base(__rhs.__has_val(), __rhs.__union()) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __rhs) noexcept(is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
- : __base(__rhs.__repr_.__has_val_, std::move(__rhs.__repr_.__union_)) {}
+ : __base(__rhs.__has_val(), std::move(__rhs.__union())) {}
template <class _OtherErr>
requires is_constructible_v<_Err, const _OtherErr&>
@@ -1423,15 +1347,15 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
is_nothrow_copy_assignable_v<_Err>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Err> && is_copy_constructible_v<_Err>)
{
- if (this->__repr_.__has_val_) {
- if (!__rhs.__repr_.__has_val_) {
- __reinit_expected(unexpect, __rhs.__repr_.__union_.__unex_);
+ if (this->__has_val()) {
+ if (!__rhs.__has_val()) {
+ __reinit_expected(unexpect, __rhs.__unex());
}
} else {
- if (__rhs.__repr_.__has_val_) {
+ if (__rhs.__has_val()) {
__reinit_expected(in_place);
} else {
- this->__repr_.__union_.__unex_ = __rhs.__repr_.__union_.__unex_;
+ this->__unex() = __rhs.__unex();
}
}
return *this;
@@ -1443,15 +1367,15 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)
{
- if (this->__repr_.__has_val_) {
- if (!__rhs.__repr_.__has_val_) {
- __reinit_expected(unexpect, std::move(__rhs.__repr_.__union_.__unex_));
+ if (this->__has_val()) {
+ if (!__rhs.__has_val()) {
+ __reinit_expected(unexpect, std::move(__rhs.__unex()));
}
} else {
- if (__rhs.__repr_.__has_val_) {
+ if (__rhs.__has_val()) {
__reinit_expected(in_place);
} else {
- this->__repr_.__union_.__unex_ = std::move(__rhs.__repr_.__union_.__unex_);
+ this->__unex() = std::move(__rhs.__unex());
}
}
return *this;
@@ -1460,10 +1384,10 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, const _OtherErr&> && is_assignable_v<_Err&, const _OtherErr&>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const unexpected<_OtherErr>& __un) {
- if (this->__repr_.__has_val_) {
+ if (this->__has_val()) {
__reinit_expected(unexpect, __un.error());
} else {
- this->__repr_.__union_.__unex_ = __un.error();
+ this->__unex() = __un.error();
}
return *this;
}
@@ -1471,16 +1395,16 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
template <class _OtherErr>
requires(is_constructible_v<_Err, _OtherErr> && is_assignable_v<_Err&, _OtherErr>)
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(unexpected<_OtherErr>&& __un) {
- if (this->__repr_.__has_val_) {
+ if (this->__has_val()) {
__reinit_expected(unexpect, std::move(__un.error()));
} else {
- this->__repr_.__union_.__unex_ = std::move(__un.error());
+ this->__unex() = std::move(__un.error());
}
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr void emplace() noexcept {
- if (!this->__repr_.__has_val_) {
+ if (!this->__has_val()) {
__reinit_expected(in_place);
}
}
@@ -1492,21 +1416,21 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
{
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
// May throw, but will re-engage `__with_val` in that case.
- __with_val.__reinit_expected(unexpect, std::move(__with_err.__repr_.__union_.__unex_));
+ __with_val.__reinit_expected(unexpect, std::move(__with_err.__unex()));
// Will not throw.
__with_err.__reinit_expected(in_place);
};
- if (this->__repr_.__has_val_) {
- if (!__rhs.__repr_.__has_val_) {
+ if (this->__has_val()) {
+ if (!__rhs.__has_val()) {
__swap_val_unex_impl(*this, __rhs);
}
} else {
- if (__rhs.__repr_.__has_val_) {
+ if (__rhs.__has_val()) {
__swap_val_unex_impl(__rhs, *this);
} else {
using std::swap;
- swap(this->__repr_.__union_.__unex_, __rhs.__repr_.__union_.__unex_);
+ swap(this->__unex(), __rhs.__unex());
}
}
}
@@ -1518,51 +1442,51 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
}
// [expected.void.obs], observers
- _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return this->__has_val(); }
- _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__repr_.__has_val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return this->__has_val(); }
_LIBCPP_HIDE_FROM_ABI constexpr void operator*() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- this->__repr_.__has_val_, "expected::operator* requires the expected to contain a value");
+ this->__has_val(), "expected::operator* requires the expected to contain a value");
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() const& {
static_assert(is_copy_constructible_v<_Err>);
- if (!this->__repr_.__has_val_) {
- std::__throw_bad_expected_access<_Err>(this->__repr_.__union_.__unex_);
+ if (!this->__has_val()) {
+ std::__throw_bad_expected_access<_Err>(this->__unex());
}
}
_LIBCPP_HIDE_FROM_ABI constexpr void value() && {
static_assert(is_copy_constructible_v<_Err> && is_move_constructible_v<_Err>);
- if (!this->__repr_.__has_val_) {
- std::__throw_bad_expected_access<_Err>(std::move(this->__repr_.__union_.__unex_));
+ if (!this->__has_val()) {
+ std::__throw_bad_expected_access<_Err>(std::move(this->__unex()));
}
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__union_.__unex_;
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return this->__unex();
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return this->__repr_.__union_.__unex_;
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return this->__unex();
}
_LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__union_.__unex_);
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return std::move(this->__unex());
}
_LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
- !this->__repr_.__has_val_, "expected::error requires the expected to contain an error");
- return std::move(this->__repr_.__union_.__unex_);
+ !this->__has_val(), "expected::error requires the expected to contain an error");
+ return std::move(this->__unex());
}
template <class _Up = _Err>
@@ -1798,16 +1722,16 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
template <class _T2, class _E2>
requires is_void_v<_T2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const expected<_T2, _E2>& __y) {
- if (__x.__repr_.__has_val_ != __y.__repr_.__has_val_) {
+ if (__x.__has_val() != __y.__has_val()) {
return false;
} else {
- return __x.__repr_.__has_val_ || static_cast<bool>(__x.__repr_.__union_.__unex_ == __y.__repr_.__union_.__unex_);
+ return __x.__has_val() || static_cast<bool>(__x.__unex() == __y.__unex());
}
}
template <class _E2>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __y) {
- return !__x.__repr_.__has_val_ && static_cast<bool>(__x.__repr_.__union_.__unex_ == __y.error());
+ return !__x.__has_val() && static_cast<bool>(__x.__unex() == __y.error());
}
};
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index e764dbd66acaa9..eab2acf1471842 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -38,7 +38,7 @@ struct BoolWithPadding {
static_assert(sizeof(std::expected<void, Empty>) == sizeof(bool));
static_assert(sizeof(std::expected<void, A>) == 2 * sizeof(int) + alignof(std::expected<void, A>));
-static_assert(sizeof(std::expected<void, B>) == sizeof(B) + alignof(std::expected<void, B>));
+static_assert(sizeof(std::expected<void, B>) == sizeof(B));
// Check that `expected`'s datasize is large enough for the parameter type(s).
static_assert(sizeof(std::expected<void, BoolWithPadding>) ==
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
index bc179b627a9a27..cf78907f6b65ea 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
@@ -52,12 +52,12 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}A program that instantiates expected<T, E> with a E that is not a valid argument for unexpected<E> is ill-formed}}
- // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
// expected-error-re@*:* {{call to deleted constructor of {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}A program that instantiates expected<T, E> with a E that is not a valid argument for unexpected<E> is ill-formed}}
+ // expected-error-re@*:* {{call to deleted constructor of {{.*}}}}
}
// Test const& overload
>From 734f5b058240e2c14f6b1d38d8d5ffce1e80a0dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 25 Oct 2023 21:11:27 +0200
Subject: [PATCH 24/55] add missing __repr and __union_t operators to be more
explicit
---
libcxx/include/__expected/expected.h | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index f691a4f5a7390c..d7f7713006bb7a 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -138,9 +138,18 @@ class __expected_base {
// it's not clear that it's implementable, given that the function is allowed to clobber
// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
union __union_t {
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&)
+ requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
+ is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&)
+ requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
+ is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>)
+ = default;
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(__union_t&&) = delete;
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t, _Args&&... __args)
@@ -215,6 +224,7 @@ class __expected_base {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(__repr&&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
@@ -1050,9 +1060,16 @@ class __expected_void_base {
// it's not clear that it's implementable, given that the function is allowed to clobber
// the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107.
union __union_t {
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = default;
- _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(const __union_t&)
+ requires(is_copy_constructible_v<_Err> && is_trivially_copy_constructible_v<_Err>)
+ = default;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t(__union_t&&)
+ requires(is_move_constructible_v<_Err> && is_trivially_move_constructible_v<_Err>)
+ = default;
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(const __union_t&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __union_t& operator=(__union_t&&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(in_place_t) : __empty_() {}
@@ -1113,6 +1130,7 @@ class __expected_void_base {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(const __repr&) = delete;
+ _LIBCPP_HIDE_FROM_ABI constexpr __repr& operator=(__repr&&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr ~__repr()
requires(is_trivially_destructible_v<_Err>)
>From 00fc6c5c21ec69d756ff6582490aae78757a9d04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 26 Oct 2023 07:00:22 +0200
Subject: [PATCH 25/55] fix invalid case style
---
libcxx/include/__expected/expected.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index d7f7713006bb7a..704552bf18d262 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -125,8 +125,8 @@ template <class _Union>
_LIBCPP_HIDE_FROM_ABI constexpr bool __expected_can_stuff_tail() {
struct __x {
private:
- _LIBCPP_NO_UNIQUE_ADDRESS _Union __union;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Union __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
return sizeof(__x) == sizeof(_Union);
}
>From 2727d6bf327195ae96a8c0d1ac9ed2df96256763 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 26 Oct 2023 11:35:06 +0200
Subject: [PATCH 26/55] try to fix layout tests for 32-bit platforms
---
.../expected.expected/no_unique_address.compile.pass.cpp | 1 +
.../expected/expected.void/no_unique_address.compile.pass.cpp | 1 +
2 files changed, 2 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
index 4d523d1ad69500..cf1909b9287323 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/no_unique_address.compile.pass.cpp
@@ -26,6 +26,7 @@ struct A {
struct B : public A {
int z_;
+ short z2_;
virtual ~B() = default;
};
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index eab2acf1471842..d533762340d1c6 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -26,6 +26,7 @@ struct A {
struct B : public A {
int z_;
+ short z2_;
virtual ~B() = default;
};
>From c7e9ba08a2a78a7cf9fd732ff5f30aa3429e77d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 26 Oct 2023 15:21:25 +0200
Subject: [PATCH 27/55] remove conditional [[no_unique_address]] of union
members
---
libcxx/include/__expected/expected.h | 42 ++++++++-----------
.../transform_error.mandates.verify.cpp | 1 +
.../transform_error.mandates.verify.cpp | 2 +-
3 files changed, 20 insertions(+), 25 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 704552bf18d262..f9ac89ff35a4fe 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,9 +88,6 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-template <class _Tp>
-concept __expected_union_member_no_unique_address = is_nothrow_move_constructible_v<_Tp>;
-
struct __expected_invoke_tag {};
template <bool _NoUnique, class _Tp>
@@ -162,12 +159,12 @@ class __expected_base {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __val_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>)
@@ -176,10 +173,8 @@ class __expected_base {
// __repr's destructor handles this
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {}
- _LIBCPP_NO_UNIQUE_ADDRESS
- __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Tp>, _Tp>::__type __val_;
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Err>,
- _Err>::__type __unex_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Tp __val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
@@ -284,9 +279,9 @@ class __expected_base {
requires(!__can_stuff_tail)
{
if (__has_val)
- return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
+ return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_);
else
- return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
@@ -298,9 +293,9 @@ class __expected_base {
requires(__can_stuff_tail)
{
if (__has_val)
- return __repr(in_place, std::forward<_OtherUnion>(__other).__val_.__v);
+ return __repr(in_place, std::forward<_OtherUnion>(__other).__val_);
else
- return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
protected:
@@ -331,10 +326,10 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr bool __has_val() const { return __repr_.__v.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& __union() { return __repr_.__v.__union_.__v; }
_LIBCPP_HIDE_FROM_ABI constexpr const __union_t& __union() const { return __repr_.__v.__union_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr _Tp& __val() { return __repr_.__v.__union_.__v.__val_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& __val() const { return __repr_.__v.__union_.__v.__val_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Tp& __val() { return __repr_.__v.__union_.__v.__val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& __val() const { return __repr_.__v.__union_.__v.__val_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
@@ -1080,7 +1075,7 @@ class __expected_void_base {
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t(
__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args)
- : __unex_(__expected_invoke_tag{}, std::forward<_Func>(__f), std::forward<_Args>(__args)...) {}
+ : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
_LIBCPP_HIDE_FROM_ABI constexpr ~__union_t()
requires(is_trivially_destructible_v<_Err>)
@@ -1092,8 +1087,7 @@ class __expected_void_base {
{}
_LIBCPP_NO_UNIQUE_ADDRESS __empty_t __empty_;
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __expected_union_member_no_unique_address<_Err>,
- _Err>::__type __unex_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
@@ -1188,7 +1182,7 @@ class __expected_void_base {
if (__has_val)
return __union_t(in_place);
else
- return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
@@ -1202,7 +1196,7 @@ class __expected_void_base {
if (__has_val)
return __repr(in_place);
else
- return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_.__v);
+ return __repr(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
protected:
@@ -1233,8 +1227,8 @@ class __expected_void_base {
_LIBCPP_HIDE_FROM_ABI constexpr bool __has_val() const { return __repr_.__v.__has_val_; }
_LIBCPP_HIDE_FROM_ABI constexpr __union_t& __union() { return __repr_.__v.__union_.__v; }
_LIBCPP_HIDE_FROM_ABI constexpr const __union_t& __union() const { return __repr_.__v.__union_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_.__v; }
- _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_.__v; }
+ _LIBCPP_HIDE_FROM_ABI constexpr _Err& __unex() { return __repr_.__v.__union_.__v.__unex_; }
+ _LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
_LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 82024a068f00d1..14c27c6286eb05 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -52,6 +52,7 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}[expected.object.general] A program that instantiates the definition of template expected<T, E> for {{.*}} is ill-formed.}}
+ // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
index cf78907f6b65ea..5f3b0be0fb627b 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
@@ -53,11 +53,11 @@ void test() {
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}A program that instantiates expected<T, E> with a E that is not a valid argument for unexpected<E> is ill-formed}}
// expected-error-re@*:* {{call to deleted constructor of {{.*}}}}
+ // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}A program that instantiates expected<T, E> with a E that is not a valid argument for unexpected<E> is ill-formed}}
- // expected-error-re@*:* {{call to deleted constructor of {{.*}}}}
}
// Test const& overload
>From f8cab00843e56f7ed1a7f891a1ee49fc3236cb0f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 26 Oct 2023 19:14:01 +0200
Subject: [PATCH 28/55] mark transform tests as failing for GCC
---
.../expected/expected.expected/monadic/transform.pass.cpp | 4 ++--
.../expected.expected/monadic/transform_error.pass.cpp | 4 ++--
.../expected/expected.void/monadic/transform_error.pass.cpp | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
index f443613fe7f343..424295bffdf2a2 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
@@ -9,8 +9,8 @@
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
-// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333, but we have a workaround to
-// avoid this issue.
+// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333
+// XFAIL: gcc
// <expected>
diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
index 84b57aea3cd231..23bf6783a14b1d 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
@@ -9,8 +9,8 @@
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
-// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333, but we have a workaround to
-// avoid this issue.
+// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333.
+// XFAIL: gcc
// <expected>
diff --git a/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
index f0e19ac3c39827..0c41d11dd66fdb 100644
--- a/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
@@ -9,8 +9,8 @@
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
-// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333, but we have a workaround to
-// avoid this issue.
+// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333
+// XFAIL: gcc
// <expected>
>From 1d31aaed45cf394711d17c7d17a66ecc992b7af1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 2 Nov 2023 20:51:58 +0100
Subject: [PATCH 29/55] simplify __expected_conditional_no_unique_address and
rename to __conditional_no_unique_address
---
libcxx/include/__expected/expected.h | 61 +++++++++++++++-------------
1 file changed, 33 insertions(+), 28 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index f9ac89ff35a4fe..0c4f076c98c7fe 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,34 +88,37 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
-struct __expected_invoke_tag {};
+struct __conditional_no_unique_address_invoke_tag {};
template <bool _NoUnique, class _Tp>
-class __expected_conditional_no_unique_address {
- struct __unique {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __unique(_Args&&... __args) : __v(std::forward<_Args>(__args)...) {}
+struct __conditional_no_unique_address;
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __unique(__expected_invoke_tag, _Func&& __f, _Args&&... __args)
- : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+template <class _Tp>
+struct __conditional_no_unique_address<true, _Tp> {
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(_Args&&... __args)
+ : __v(std::forward<_Args>(__args)...) {}
- _Tp __v;
- };
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(
+ __conditional_no_unique_address_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
- struct __no_unique {
- template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __no_unique(_Args&&... __args) : __v(std::forward<_Args>(__args)...) {}
+ _LIBCPP_NO_UNIQUE_ADDRESS _Tp __v;
+};
- template <class _Func, class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __no_unique(__expected_invoke_tag, _Func&& __f, _Args&&... __args)
- : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
+template <class _Tp>
+struct __conditional_no_unique_address<false, _Tp> {
+ template <class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(_Args&&... __args)
+ : __v(std::forward<_Args>(__args)...) {}
- _LIBCPP_NO_UNIQUE_ADDRESS _Tp __v;
- };
+ template <class _Func, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(
+ __conditional_no_unique_address_invoke_tag, _Func&& __f, _Args&&... __args)
+ : __v(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {}
-public:
- using __type = std::conditional<_NoUnique, __no_unique, __unique>::type;
+ _Tp __v;
};
template <class _Union>
@@ -203,7 +206,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
requires(!__can_stuff_tail)
- : __union_(__expected_invoke_tag{},
+ : __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -284,7 +287,7 @@ class __expected_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__can_stuff_tail, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
@@ -306,7 +309,8 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
requires(__can_stuff_tail)
- : __repr_(__expected_invoke_tag{}, [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
+ : __repr_(__conditional_no_unique_address_invoke_tag{},
+ [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
if constexpr (__can_stuff_tail)
@@ -332,7 +336,7 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__can_stuff_tail, __repr> __repr_;
};
template <class _Tp, class _Err>
@@ -1110,7 +1114,7 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
requires(!__can_stuff_tail)
- : __union_(__expected_invoke_tag{},
+ : __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -1185,7 +1189,7 @@ class __expected_void_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< __can_stuff_tail, __union_t>::__type __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__can_stuff_tail, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
@@ -1207,7 +1211,8 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(bool __has_val, _OtherUnion&& __other)
requires(__can_stuff_tail)
- : __repr_(__expected_invoke_tag{}, [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
+ : __repr_(__conditional_no_unique_address_invoke_tag{},
+ [&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
if constexpr (__can_stuff_tail)
@@ -1231,7 +1236,7 @@ class __expected_void_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __expected_conditional_no_unique_address< !__can_stuff_tail, __repr>::__type __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__can_stuff_tail, __repr> __repr_;
};
template <class _Tp, class _Err>
>From fa5eacda7f5107c6211d7c86d0b485114c3f8a83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 2 Nov 2023 20:53:19 +0100
Subject: [PATCH 30/55] add comment to __conditional_no_unique_address
suggested by ldionne
---
libcxx/include/__expected/expected.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 0c4f076c98c7fe..d502dd87e1d4e3 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -90,6 +90,10 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
struct __conditional_no_unique_address_invoke_tag {};
+// This class implements an object with `[[no_unique_address]]` conditionally applied to it,
+// based on the value of `_NoUnique`.
+//
+// If we had a language feature, this class would basically be replaced by `[[no_unique_address(condition)]]`.
template <bool _NoUnique, class _Tp>
struct __conditional_no_unique_address;
>From 126fb938ffef27d85acf9f4d23f1a36595d1a2fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 2 Nov 2023 21:04:56 +0100
Subject: [PATCH 31/55] add another comment explaining usage of
__conditional_no_unique_address
---
libcxx/include/__expected/expected.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index d502dd87e1d4e3..1cd0a4144bd2a4 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -93,6 +93,12 @@ struct __conditional_no_unique_address_invoke_tag {};
// This class implements an object with `[[no_unique_address]]` conditionally applied to it,
// based on the value of `_NoUnique`.
//
+// A member of this class must always have `[[no_unique_address]]` applied to
+// it. Otherwise, the `[[no_unique_address]]` in the "`_NoUnique == true`" case
+// would not have any effect. In the `false` case, the `__v` is not
+// `[[no_unique_address]]`, so nullifies the effects of the "outer"
+// `[[no_unique_address]]` regarding data layout.
+//
// If we had a language feature, this class would basically be replaced by `[[no_unique_address(condition)]]`.
template <bool _NoUnique, class _Tp>
struct __conditional_no_unique_address;
>From 0109b25da3ff6db96b9451c4ac672017cdd25e0b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 2 Nov 2023 21:18:07 +0100
Subject: [PATCH 32/55] rename __expected_can_stuff_tail to
__fits_in_tail_padding and make more general
Suggested by ldionne.
---
libcxx/include/__expected/expected.h | 67 ++++++++++++++--------------
1 file changed, 34 insertions(+), 33 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 1cd0a4144bd2a4..d07d031d9bf568 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -131,15 +131,16 @@ struct __conditional_no_unique_address<false, _Tp> {
_Tp __v;
};
-template <class _Union>
-_LIBCPP_HIDE_FROM_ABI constexpr bool __expected_can_stuff_tail() {
+// This function returns whether the type `_Second` can be stuffed into the tail padding
+// of the `_First` type if both of them are given `[[no_unique_address]]`.
+template <class _First, class _Second>
+inline constexpr bool __fits_in_tail_padding = []() {
struct __x {
- private:
- _LIBCPP_NO_UNIQUE_ADDRESS _Union __union_;
- _LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
+ _LIBCPP_NO_UNIQUE_ADDRESS _First __first;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Second __second;
};
- return sizeof(__x) == sizeof(_Union);
-}
+ return sizeof(__x) == sizeof(_First);
+}();
template <class _Tp, class _Err>
class __expected_base {
@@ -190,7 +191,7 @@ class __expected_base {
_LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
- static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
+ static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
struct __repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
@@ -215,7 +216,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
: __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -245,13 +246,13 @@ class __expected_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
+ requires(!__put_flag_in_tail && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
{
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
+ requires(!__put_flag_in_tail && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
{
__destroy_union_member();
std::destroy_at(&__union_.__v);
@@ -259,7 +260,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
std::construct_at(&__union_.__v, in_place, std::forward<_Args>(__args)...);
__has_val_ = true;
@@ -267,7 +268,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
__has_val_ = false;
@@ -289,7 +290,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
if (__has_val)
return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_);
@@ -297,13 +298,13 @@ class __expected_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__can_stuff_tail, __union_t> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__put_flag_in_tail, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail)
+ requires(__put_flag_in_tail)
{
if (__has_val)
return __repr(in_place, std::forward<_OtherUnion>(__other).__val_);
@@ -318,12 +319,12 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail)
+ requires(__put_flag_in_tail)
: __repr_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
- if constexpr (__can_stuff_tail)
+ if constexpr (__put_flag_in_tail)
std::destroy_at(&__repr_.__v);
else
__repr_.__v.__destroy_union();
@@ -331,7 +332,7 @@ class __expected_base {
template <class _Tag, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- if constexpr (__can_stuff_tail)
+ if constexpr (__put_flag_in_tail)
std::construct_at(&__repr_.__v, __tag, std::forward<_Args>(__args)...);
else
__repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
@@ -346,7 +347,7 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__can_stuff_tail, __repr> __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__put_flag_in_tail, __repr> __repr_;
};
template <class _Tp, class _Err>
@@ -1104,7 +1105,7 @@ class __expected_void_base {
_LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
- static constexpr bool __can_stuff_tail = __expected_can_stuff_tail<__union_t>();
+ static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
struct __repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
@@ -1123,7 +1124,7 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
: __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -1151,20 +1152,20 @@ class __expected_void_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail && is_trivially_destructible_v<_Err>)
+ requires(!__put_flag_in_tail && is_trivially_destructible_v<_Err>)
{
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__can_stuff_tail && !is_trivially_destructible_v<_Err>)
+ requires(!__put_flag_in_tail && !is_trivially_destructible_v<_Err>)
{
__destroy_union_member();
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
std::construct_at(&__union_.__v, in_place);
__has_val_ = true;
@@ -1172,7 +1173,7 @@ class __expected_void_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
__has_val_ = false;
@@ -1191,7 +1192,7 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
- requires(!__can_stuff_tail)
+ requires(!__put_flag_in_tail)
{
if (__has_val)
return __union_t(in_place);
@@ -1199,13 +1200,13 @@ class __expected_void_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__can_stuff_tail, __union_t> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__put_flag_in_tail, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __repr __make_repr(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail)
+ requires(__put_flag_in_tail)
{
if (__has_val)
return __repr(in_place);
@@ -1220,12 +1221,12 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(bool __has_val, _OtherUnion&& __other)
- requires(__can_stuff_tail)
+ requires(__put_flag_in_tail)
: __repr_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_repr(__has_val, std::forward<_OtherUnion>(__other)); }) {}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy() {
- if constexpr (__can_stuff_tail)
+ if constexpr (__put_flag_in_tail)
std::destroy_at(&__repr_.__v);
else
__repr_.__v.__destroy_union();
@@ -1233,7 +1234,7 @@ class __expected_void_base {
template <class _Tag, class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct(_Tag __tag, _Args&&... __args) {
- if constexpr (__can_stuff_tail)
+ if constexpr (__put_flag_in_tail)
std::construct_at(&__repr_.__v, __tag, std::forward<_Args>(__args)...);
else
__repr_.__v.__construct_union(__tag, std::forward<_Args>(__args)...);
@@ -1246,7 +1247,7 @@ class __expected_void_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__can_stuff_tail, __repr> __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__put_flag_in_tail, __repr> __repr_;
};
template <class _Tp, class _Err>
>From cb7a0b9152bc58919999a11bd399de51e2ab3135 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Thu, 2 Nov 2023 21:47:05 +0100
Subject: [PATCH 33/55] add comment detailing the distinction between
__make_repr and __make_union
---
libcxx/include/__expected/expected.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index d07d031d9bf568..5b1d8e7b05549b 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -317,6 +317,25 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
: __repr_(std::forward<_Args>(__args)...) {}
+ // In case we copy/move construct from another `expected` we need to create
+ // our `expected` so that it either has a value or not, depending on the "has
+ // value" flag of the other `expected`. To do this without falling back on
+ // `std::construct_at` we rely on guaranteed copy elision using two helper
+ // functions `__make_repr` and `__make_union`. There have to be two since
+ // there are two data layouts with different members being
+ // `[[no_unique_address]]`. GCC (as of version 13) does not do guaranteed
+ // copy elision when initializing `[[no_unique_address]]` members. The two
+ // cases are:
+ //
+ // - `__make_repr`: This is used when the "has value" flag lives in the tail
+ // of the union. In this case, the `__repr` member is _not_
+ // `[[no_unique_address]]`.
+ // - `__make_union`: When the "has value" flag does _not_ fit in the tail of
+ // the union, the `__repr` member is `[[no_unique_address]]` and the union
+ // is not.
+ //
+ // This constructor "catches" the first case and leaves the second case to
+ // `__union_t`, its constructors and `__make_union`.
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(bool __has_val, _OtherUnion&& __other)
requires(__put_flag_in_tail)
>From 6cf38930ad8258fcb9d44654b8cc1cdaebc09362 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 2 Dec 2023 16:51:39 +0100
Subject: [PATCH 34/55] add tests that check for invalid writes to potential
tail padding
---
.../assign/assign.U.pass.cpp | 14 ++
.../assign/assign.copy.pass.cpp | 23 +++
.../assign/assign.move.pass.cpp | 23 +++
.../expected.expected/assign/emplace.pass.cpp | 14 ++
.../swap/member.swap.pass.cpp | 22 +++
.../expected.void/assign/assign.copy.pass.cpp | 22 +++
.../expected.void/assign/assign.move.pass.cpp | 22 +++
.../assign/assign.unexpected.copy.pass.cpp | 16 +++
.../assign/assign.unexpected.move.pass.cpp | 17 +++
.../expected.void/swap/member.swap.pass.cpp | 22 +++
libcxx/test/std/utilities/expected/types.h | 136 ++++++++++++++++++
11 files changed, 331 insertions(+)
diff --git a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.U.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.U.pass.cpp
index 1c8750b7acd100..2d3b03689b1d91 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.U.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.U.pass.cpp
@@ -310,6 +310,20 @@ constexpr bool test() {
assert(e.value().j == 8);
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true> e1(std::unexpect);
+ e1 = 42;
+ assert(e1.check());
+ }
+ {
+ CheckForInvalidWrites<false> e1(std::unexpect);
+ e1 = true;
+ assert(e1.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.copy.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.copy.pass.cpp
index 03fe888b0a5e7f..2f5291332355ca 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.copy.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.copy.pass.cpp
@@ -240,6 +240,29 @@ constexpr bool test() {
assert(e1.error().data_ == 10);
assert(oldState.copyAssignCalled);
}
+
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true> e1(std::unexpect);
+ CheckForInvalidWrites<true> e2;
+
+ e1 = e2;
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ {
+ CheckForInvalidWrites<false> e1(std::unexpect);
+ CheckForInvalidWrites<false> e2;
+
+ e1 = e2;
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.move.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.move.pass.cpp
index 8c419afd10729f..065827ae652c98 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/assign/assign.move.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/assign/assign.move.pass.cpp
@@ -258,6 +258,29 @@ constexpr bool test() {
assert(e1.error().data_ == 10);
assert(oldState.moveAssignCalled);
}
+
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true> e1(std::unexpect);
+ CheckForInvalidWrites<true> e2;
+
+ e1 = std::move(e2);
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ {
+ CheckForInvalidWrites<false> e1(std::unexpect);
+ CheckForInvalidWrites<false> e2;
+
+ e1 = std::move(e2);
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.expected/assign/emplace.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/assign/emplace.pass.cpp
index 491de2dff03312..7e37f8bdf4abc0 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/assign/emplace.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/assign/emplace.pass.cpp
@@ -80,6 +80,20 @@ constexpr bool test() {
assert(e.has_value());
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true> e;
+ e.emplace();
+ assert(e.check());
+ }
+ {
+ CheckForInvalidWrites<false> e;
+ e.emplace();
+ assert(e.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.expected/swap/member.swap.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/swap/member.swap.pass.cpp
index 34782303909e2a..f19599d43b32df 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/swap/member.swap.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/swap/member.swap.pass.cpp
@@ -227,6 +227,28 @@ constexpr bool test() {
}
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true> x(std::unexpect);
+ CheckForInvalidWrites<true> y;
+
+ x.swap(y);
+
+ assert(x.check());
+ assert(y.check());
+ }
+ {
+ CheckForInvalidWrites<false> x(std::unexpect);
+ CheckForInvalidWrites<false> y;
+
+ x.swap(y);
+
+ assert(x.check());
+ assert(y.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.void/assign/assign.copy.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/assign/assign.copy.pass.cpp
index b1968bcc242403..a51916f874eeab 100644
--- a/libcxx/test/std/utilities/expected/expected.void/assign/assign.copy.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/assign/assign.copy.pass.cpp
@@ -99,6 +99,28 @@ constexpr bool test() {
assert(state.copyAssignCalled);
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true, true> e1;
+ CheckForInvalidWrites<true, true> e2(std::unexpect);
+
+ e1 = e2;
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ {
+ CheckForInvalidWrites<false, true> e1;
+ CheckForInvalidWrites<false, true> e2(std::unexpect);
+
+ e1 = e2;
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.void/assign/assign.move.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/assign/assign.move.pass.cpp
index e6a29cd62583be..60ae0346f7af1e 100644
--- a/libcxx/test/std/utilities/expected/expected.void/assign/assign.move.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/assign/assign.move.pass.cpp
@@ -125,6 +125,28 @@ constexpr bool test() {
assert(state.moveAssignCalled);
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true, true> e1;
+ CheckForInvalidWrites<true, true> e2(std::unexpect);
+
+ e1 = std::move(e2);
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ {
+ CheckForInvalidWrites<false, true> e1;
+ CheckForInvalidWrites<false, true> e2(std::unexpect);
+
+ e1 = std::move(e2);
+
+ assert(e1.check());
+ assert(e2.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.copy.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.copy.pass.cpp
index 1ae96530e528e8..699597d243c19b 100644
--- a/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.copy.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.copy.pass.cpp
@@ -91,6 +91,22 @@ constexpr bool test() {
assert(state1.copyAssignCalled);
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true, true> e;
+ std::unexpected<int> un(std::in_place, 42);
+ e = un;
+ assert(e.check());
+ }
+ {
+ CheckForInvalidWrites<false, true> e;
+ std::unexpected<bool> un(std::in_place, true);
+ e = un;
+ assert(e.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.move.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.move.pass.cpp
index ea947715af28f1..641eb4927a724e 100644
--- a/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.move.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/assign/assign.unexpected.move.pass.cpp
@@ -172,6 +172,23 @@ constexpr bool test() {
assert(e1.error().data_ == 10);
assert(oldState.moveAssignCalled);
}
+
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true, true> e;
+ std::unexpected<int> un(std::in_place, 42);
+ e = std::move(un);
+ assert(e.check());
+ }
+ {
+ CheckForInvalidWrites<false, true> e;
+ std::unexpected<bool> un(std::in_place, true);
+ e = std::move(un);
+ assert(e.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/expected.void/swap/member.swap.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/swap/member.swap.pass.cpp
index 07980dee13c1e9..25601af39a3162 100644
--- a/libcxx/test/std/utilities/expected/expected.void/swap/member.swap.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/swap/member.swap.pass.cpp
@@ -139,6 +139,28 @@ constexpr bool test() {
assert(y.has_value());
}
+ // CheckForInvalidWrites
+ {
+ {
+ CheckForInvalidWrites<true, true> x(std::unexpect);
+ CheckForInvalidWrites<true, true> y;
+
+ x.swap(y);
+
+ assert(x.check());
+ assert(y.check());
+ }
+ {
+ CheckForInvalidWrites<false, true> x(std::unexpect);
+ CheckForInvalidWrites<false, true> y;
+
+ x.swap(y);
+
+ assert(x.check());
+ assert(y.check());
+ }
+ }
+
return true;
}
diff --git a/libcxx/test/std/utilities/expected/types.h b/libcxx/test/std/utilities/expected/types.h
index 90768ed8e7520b..c576e79e16ceea 100644
--- a/libcxx/test/std/utilities/expected/types.h
+++ b/libcxx/test/std/utilities/expected/types.h
@@ -199,4 +199,140 @@ static_assert(!std::is_trivially_move_constructible_v<TailClobbererNonTrivialMov
static_assert(std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<0, true>>);
static_assert(!std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<0, false>>);
+// The `CheckForInvalidWrites` class recreates situations where other objects
+// may be placed into a `std::expected`'s tail padding. With a template
+// parameter `WithPaddedExpected` two cases can be tested:
+//
+// 1. The `std::expected<T, E>` itself has padding, because `T`/`E` _don't_
+// have tail padding. This is modelled by `CheckForInvalidWrites<true>`
+// which has a (potential) data layout like this:
+//
+// +- `expected`'s "has value" flag
+// |
+// | +- `please_dont_overwrite_me`
+// | |
+// /---int---\ | /----------^-------\
+// 00 00 00 00 01 01 01 01 01 01 01 01
+// \--v---/
+// |
+// |
+// +- `expected`'s tail padding which
+// gets repurposed by `please_dont_overwrite_me`
+//
+// 2. There is tail padding in the union of `T` and `E` which means the
+// "has value" flag can be put into this tail padding. In this case, the
+// `std::expected` itself _must not_ have any tail padding as it may get
+// overwritten on mutating operations such as `emplace()`. This case is
+// modelled by `CheckForInvalidWrites<false>` with a (potential) data
+// layout like this:
+//
+// +- bool
+// | +- please_dont_overwrite_me
+// | +- "has value" flag |
+// | | /--------^---------\
+// 00 00 00 00 00 00 00 00 01 01 01 01 01 01 01 00
+// \---padding-----/ |
+// +- `CheckForInvalidWrites`
+// padding
+//
+// Note that other implementation strategies are viable, including one that
+// doesn't make use of `[[no_unique_address]]`. But if an implementation uses
+// the strategy above, it must make sure that those tail padding bytes are not
+// overwritten improperly on operations such as `emplace()`.
+
+struct BoolWithPadding {
+ constexpr explicit BoolWithPadding() noexcept : BoolWithPadding(false) {}
+ constexpr BoolWithPadding(bool val) noexcept {
+ if (!std::is_constant_evaluated()) {
+ std::memset(this, 0, sizeof(*this));
+ }
+ val_ = val;
+ }
+ constexpr BoolWithPadding(const BoolWithPadding& other) noexcept : BoolWithPadding(other.val_) {}
+ constexpr BoolWithPadding& operator=(const BoolWithPadding& other) noexcept {
+ val_ = other.val_;
+ return *this;
+ }
+ // The previous data layout of libc++'s `expected` required `T` to be
+ // trivially move constructible to employ the `[[no_unique_address]]`
+ // optimization. To trigger bugs with the old implementation, make
+ // `BoolWithPadding` trivially move constructible.
+ constexpr BoolWithPadding(BoolWithPadding&&) = default;
+
+private:
+ alignas(8) bool val_;
+};
+
+struct IntWithoutPadding {
+ constexpr explicit IntWithoutPadding() noexcept : IntWithoutPadding(0) {}
+ constexpr IntWithoutPadding(int val) noexcept {
+ if (!std::is_constant_evaluated()) {
+ std::memset(this, 0, sizeof(*this));
+ }
+ val_ = val;
+ }
+ constexpr IntWithoutPadding(const IntWithoutPadding& other) noexcept : IntWithoutPadding(other.val_) {}
+ constexpr IntWithoutPadding& operator=(const IntWithoutPadding& other) noexcept {
+ val_ = other.val_;
+ return *this;
+ }
+ // See comment on `BoolWithPadding`.
+ constexpr IntWithoutPadding(IntWithoutPadding&&) = default;
+
+private:
+ int val_;
+};
+
+template <bool WithPaddedExpected, bool ExpectedVoid>
+struct CheckForInvalidWritesBaseImpl;
+template <>
+struct CheckForInvalidWritesBaseImpl<true, false> {
+ using type = std::expected<IntWithoutPadding, bool>;
+};
+template <>
+struct CheckForInvalidWritesBaseImpl<false, false> {
+ using type = std::expected<BoolWithPadding, bool>;
+};
+template <>
+struct CheckForInvalidWritesBaseImpl<true, true> {
+ using type = std::expected<void, IntWithoutPadding>;
+};
+template <>
+struct CheckForInvalidWritesBaseImpl<false, true> {
+ using type = std::expected<void, BoolWithPadding>;
+};
+
+template <bool WithPaddedExpected, bool ExpectedVoid>
+using CheckForInvalidWritesBase = typename CheckForInvalidWritesBaseImpl<WithPaddedExpected, ExpectedVoid>::type;
+
+template <bool WithPaddedExpected, bool ExpectedVoid = false>
+struct CheckForInvalidWrites : public CheckForInvalidWritesBase<WithPaddedExpected, ExpectedVoid> {
+ constexpr CheckForInvalidWrites() = default;
+ constexpr CheckForInvalidWrites(std::unexpect_t)
+ : CheckForInvalidWritesBase<WithPaddedExpected, ExpectedVoid>(std::unexpect) {}
+
+ constexpr CheckForInvalidWrites& operator=(const CheckForInvalidWrites& other) {
+ CheckForInvalidWritesBase<WithPaddedExpected, ExpectedVoid>::operator=(other);
+ return *this;
+ }
+
+ constexpr CheckForInvalidWrites& operator=(CheckForInvalidWrites&& other) {
+ CheckForInvalidWritesBase<WithPaddedExpected, ExpectedVoid>::operator=(std::move(other));
+ return *this;
+ }
+
+ using CheckForInvalidWritesBase<WithPaddedExpected, ExpectedVoid>::operator=;
+
+ const bool please_dont_overwrite_me[7] = {true, true, true, true, true, true, true};
+
+ constexpr bool check() {
+ for (bool i : please_dont_overwrite_me) {
+ if (!i) {
+ return false;
+ }
+ }
+ return true;
+ }
+};
+
#endif // TEST_STD_UTILITIES_EXPECTED_TYPES_H
>From f6c673581e4cff9c3b39ac54e8e62c4ec3aa5e3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 2 Dec 2023 17:46:36 +0100
Subject: [PATCH 35/55] fix GCC warning about multiline comments
---
libcxx/test/std/utilities/expected/types.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libcxx/test/std/utilities/expected/types.h b/libcxx/test/std/utilities/expected/types.h
index c576e79e16ceea..81e295aa1dcd76 100644
--- a/libcxx/test/std/utilities/expected/types.h
+++ b/libcxx/test/std/utilities/expected/types.h
@@ -211,7 +211,7 @@ static_assert(!std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<
// |
// | +- `please_dont_overwrite_me`
// | |
-// /---int---\ | /----------^-------\
+// /---int---\ | /----------^-------\ //
// 00 00 00 00 01 01 01 01 01 01 01 01
// \--v---/
// |
@@ -229,7 +229,7 @@ static_assert(!std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<
// +- bool
// | +- please_dont_overwrite_me
// | +- "has value" flag |
-// | | /--------^---------\
+// | | /--------^---------\ //
// 00 00 00 00 00 00 00 00 01 01 01 01 01 01 01 00
// \---padding-----/ |
// +- `CheckForInvalidWrites`
>From 41b9459f90e79d865cc22472e59c4ab4921f6a49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sun, 3 Dec 2023 11:05:14 +0100
Subject: [PATCH 36/55] try to fix transform_error.mandates.verify.cpp test on
clang-cl
---
.../expected.expected/transform_error.mandates.verify.cpp | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 14c27c6286eb05..960237574f59a9 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -52,7 +52,11 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}[expected.object.general] A program that instantiates the definition of template expected<T, E> for {{.*}} is ill-formed.}}
+#if defined(TEST_COMPILER_CLANG) && defined(_MSC_VER)
+ // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}, which is a Microsoft extension}}
+#else
// expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
+#endif
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
>From e00e21e73bd4b9f15627266ed32088891f61b221 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 12 Jan 2024 20:49:35 +0100
Subject: [PATCH 37/55] add in_place_t tag to __conditional_no_unique_address
constructor
---
libcxx/include/__expected/expected.h | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 5b1d8e7b05549b..b64dd0be8b604e 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -106,7 +106,7 @@ struct __conditional_no_unique_address;
template <class _Tp>
struct __conditional_no_unique_address<true, _Tp> {
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(_Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(in_place_t, _Args&&... __args)
: __v(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -120,7 +120,7 @@ struct __conditional_no_unique_address<true, _Tp> {
template <class _Tp>
struct __conditional_no_unique_address<false, _Tp> {
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(_Args&&... __args)
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __conditional_no_unique_address(in_place_t, _Args&&... __args)
: __v(std::forward<_Args>(__args)...) {}
template <class _Func, class... _Args>
@@ -198,21 +198,21 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_in_place_from_invoke_tag __tag,
_Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(true) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(true) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
_Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
@@ -315,7 +315,7 @@ class __expected_base {
protected:
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_base(_Args&&... __args)
- : __repr_(std::forward<_Args>(__args)...) {}
+ : __repr_(in_place, std::forward<_Args>(__args)...) {}
// In case we copy/move construct from another `expected` we need to create
// our `expected` so that it either has a value or not, depending on the "has
@@ -1130,16 +1130,16 @@ class __expected_void_base {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
template <class... _Args>
- _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag) : __union_(__tag), __has_val_(true) {}
+ _LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(in_place_t __tag) : __union_(in_place, __tag), __has_val_(true) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(unexpect_t __tag, _Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(std::__expected_construct_unexpected_from_invoke_tag __tag,
_Args&&... __args)
- : __union_(__tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ : __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(false) {}
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
@@ -1236,7 +1236,7 @@ class __expected_void_base {
protected:
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(_Args&&... __args)
- : __repr_(std::forward<_Args>(__args)...) {}
+ : __repr_(in_place, std::forward<_Args>(__args)...) {}
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __expected_void_base(bool __has_val, _OtherUnion&& __other)
>From 27783715258a4c3ca1c14b40eafa091597ae7150 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 13 Jan 2024 08:41:57 +0100
Subject: [PATCH 38/55] make __union_ unconditionally no_unique_address to see
if everything works
---
libcxx/include/__expected/expected.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index b64dd0be8b604e..37df01e3a5e17b 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -298,7 +298,10 @@ class __expected_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__put_flag_in_tail, __union_t> __union_;
+ // XXX: refactor before merge -- the condition is set to `true` in order
+ // to check if everything works if the `__union_` is unconditionally
+ // `[[no_unique_address]]`.
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<true, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
>From 6363349bbeb6a1da23fc0d9d26f07bce367a3acb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Tue, 16 Jan 2024 20:39:30 +0100
Subject: [PATCH 39/55] Update
libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
Co-authored-by: Louis Dionne <ldionne.2 at gmail.com>
---
.../expected/expected.void/monadic/transform_error.pass.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
index 0c41d11dd66fdb..cd6e5a5038d28d 100644
--- a/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.void/monadic/transform_error.pass.cpp
@@ -10,7 +10,7 @@
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333
-// XFAIL: gcc
+// XFAIL: gcc-13
// <expected>
>From e25009ea6113421c551d8af1efcada737d7db519 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 17 Jan 2024 19:36:03 +0100
Subject: [PATCH 40/55] fix typo
---
.../expected.expected/transform_error.mandates.verify.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 960237574f59a9..c512ddc27ff63c 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -7,7 +7,7 @@
//===----------------------------------------------------------------------===//
// Clang-18 fixed some spurious clang diagnostics. Once clang-18 is the
-// minumum required version these obsolete tests can be removed.
+// minimum required version these obsolete tests can be removed.
// TODO(LLVM-20) remove spurious clang diagnostic tests.
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
>From 3dafea336951309cce53f2192571148460bd4419 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 17 Jan 2024 19:36:22 +0100
Subject: [PATCH 41/55] try to workaround clang-cl CI failure by excluding
clang-cl from this test
---
.../expected.expected/transform_error.mandates.verify.cpp | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index c512ddc27ff63c..5bf094bf37709d 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -12,6 +12,10 @@
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// With clang-cl, some warnings have a 'which is a Microsoft extension' suffix
+// which break the tests.
+// XFAIL: msvc
+
// Test the mandates
// template<class F> constexpr auto transform_error(F&& f) &;
@@ -52,11 +56,7 @@ void test() {
e.transform_error(return_unexpected<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
// expected-error-re@*:* {{static assertion failed {{.*}}[expected.object.general] A program that instantiates the definition of template expected<T, E> for {{.*}} is ill-formed.}}
-#if defined(TEST_COMPILER_CLANG) && defined(_MSC_VER)
- // expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}, which is a Microsoft extension}}
-#else
// expected-error-re@*:* {{union member {{.*}} has reference type {{.*}}}}
-#endif
e.transform_error(return_no_object<int&>); // expected-error-re@*:* {{static assertion failed {{.*}}The result of {{.*}} must be a valid template argument for unexpected}}
// expected-error-re@*:* 0-1 {{{{(excess elements in struct initializer|no matching constructor for initialization of)}}{{.*}}}}
>From d9f648e573b9f14a0d4b9ce35b0f19b5c8ad205f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Wed, 17 Jan 2024 19:37:27 +0100
Subject: [PATCH 42/55] Revert "make __union_ unconditionally no_unique_address
to see if everything works"
This reverts commit 4bb1d3e3460c54f0f26a92ed9dbbfbcf4edad1fc.
---
libcxx/include/__expected/expected.h | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 37df01e3a5e17b..b64dd0be8b604e 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -298,10 +298,7 @@ class __expected_base {
return __union_t(unexpect, std::forward<_OtherUnion>(__other).__unex_);
}
- // XXX: refactor before merge -- the condition is set to `true` in order
- // to check if everything works if the `__union_` is unconditionally
- // `[[no_unique_address]]`.
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<true, __union_t> __union_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__put_flag_in_tail, __union_t> __union_;
_LIBCPP_NO_UNIQUE_ADDRESS bool __has_val_;
};
>From 6e65e00193f719c0de22b57ec051fa43c3c30b71 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 05:59:31 +0100
Subject: [PATCH 43/55] add issue link to comment on
libcxx/test/std/utilities/expected/types.h
---
libcxx/test/std/utilities/expected/types.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/libcxx/test/std/utilities/expected/types.h b/libcxx/test/std/utilities/expected/types.h
index 81e295aa1dcd76..2b6983fb399c67 100644
--- a/libcxx/test/std/utilities/expected/types.h
+++ b/libcxx/test/std/utilities/expected/types.h
@@ -200,7 +200,8 @@ static_assert(std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<0
static_assert(!std::is_nothrow_move_constructible_v<TailClobbererNonTrivialMove<0, false>>);
// The `CheckForInvalidWrites` class recreates situations where other objects
-// may be placed into a `std::expected`'s tail padding. With a template
+// may be placed into a `std::expected`'s tail padding (see
+// https://github.com/llvm/llvm-project/issues/70494). With a template
// parameter `WithPaddedExpected` two cases can be tested:
//
// 1. The `std::expected<T, E>` itself has padding, because `T`/`E` _don't_
>From 1d90c611f3e4da86440d692414920e841615667b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 06:09:01 +0100
Subject: [PATCH 44/55] replace precondition comments with
_LIBCPP_ASSERT_INTERNAL
---
libcxx/include/__expected/expected.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index b64dd0be8b604e..4a62794113fd92 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -1371,17 +1371,19 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr ~expected() = default;
private:
- // precondition: has_value()
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(unexpect_t, _Args&&... __args) {
+ _LIBCPP_ASSERT_INTERNAL(this->__has_val(), "__reinit_expected(unexpect_t, ...) needs value to be set");
+
this->__destroy();
auto __trans = std::__make_exception_guard([&] { this->__construct(in_place); });
this->__construct(unexpect, std::forward<_Args>(__args)...);
__trans.__complete();
}
- // precondition: !has_value()
_LIBCPP_HIDE_FROM_ABI constexpr void __reinit_expected(in_place_t) {
+ _LIBCPP_ASSERT_INTERNAL(!this->__has_val(), "__reinit_expected(in_place_t, ...) needs value to be unset");
+
this->__destroy();
this->__construct(in_place);
}
>From ba2d4cd8f3183c088f83b3ee6aca5e2889912620 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 06:38:33 +0100
Subject: [PATCH 45/55] add comment to the __expected_base class
---
libcxx/include/__expected/expected.h | 64 ++++++++++++++++++++++++++++
1 file changed, 64 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 4a62794113fd92..52cc1dc38f5a05 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -142,6 +142,70 @@ inline constexpr bool __fits_in_tail_padding = []() {
return sizeof(__x) == sizeof(_First);
}();
+// This class implements the storage used by `std::expected`. We have a few
+// goals for this storage:
+// 1. Whenever the underlying {_Tp | _Unex} combination has free bytes in its
+// tail padding, we should reuse it to store the bool discriminator of the
+// expected, so as to save space.
+// 2. Whenever the `expected<_Tp, _Unex>` as a whole has free bytes in its tail
+// padding, we should allow an object following the expected to be stored in
+// its tail padding.
+// 3. However, we never want a user object (say `X`) that would follow an
+// `expected<_Tp, _Unex>` to be stored in the padding bytes of the
+// underlying {_Tp | _Unex} union, if any. That is because we use
+// `construct_at` on that union, which would end up overwriting the `X`
+// member if it is stored in the tail padding of the union.
+//
+// To achieve this, `__expected_base`'s logic is implemented in an inner
+// `__repr` class. `__expected_base` holds one `__repr` member which is
+// conditionally `[[no_unique_address]]`. The `__repr` class holds the
+// underlying {_Tp | _Unex} union and a boolean "has value" flag.
+//
+// Which one of the `__repr_`/`__union_` members is `[[no_unique_address]]`
+// depends on whether the "has value" boolean fits into the tail padding of
+// the underlying {_Tp | _Unex} union:
+//
+// - In case the "has value" bool fits into the tail padding of the union, the
+// whole `__repr_` member is _not_ `[[no_unique_address]]` as it needs to be
+// transparently replaced on `emplace()`/`swap()` etc.
+// - In case the "has value" bool does not fit into the tail padding of the
+// union, only the union member must be transparently replaced (therefore is
+// _not_ `[[no_unique_address]]`) and the "has value" flag must be adjusted
+// manually.
+//
+// This way, the member that is transparently replaced on mutating operations
+// is never `[[no_unique_address]]`, satisfying the requirements from
+// "[basic.life]" in the standard.
+//
+// Stripped away of all superfluous elements, the layout of `__expected_base`
+// then looks like this:
+//
+// template <class Tp, class Err>
+// class expected_base {
+// union union_t {
+// [[no_unique_address]] Tp val;
+// [[no_unique_address]] Err unex;
+// };
+//
+// struct repr {
+// private:
+// // If "has value" fits into the tail, this should be
+// // `[[no_unique_address]]`, otherwise not.
+// [[no_unique_address]] conditional_no_unique_address<
+// fits_in_tail_padding<union_t, bool>,
+// union_t>::type union_;
+// [[no_unique_address]] bool has_val_;
+// };
+//
+// protected:
+// // If "has value" fits into the tail, this must _not_ be
+// // `[[no_unique_address]]` so that we fill out the
+// // complete `expected` object.
+// [[no_unique_address]] conditional_no_unique_address<
+// !fits_in_tail_padding<union_t, bool>,
+// repr>::type repr_;
+// };
+//
template <class _Tp, class _Err>
class __expected_base {
// use named union because [[no_unique_address]] cannot be applied to an unnamed union,
>From b6727b6fe96c4a98cb6dcbe10d6d120c67e8c406 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 06:42:41 +0100
Subject: [PATCH 46/55] Update
libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
Co-authored-by: Louis Dionne <ldionne.2 at gmail.com>
---
.../expected/expected.void/no_unique_address.compile.pass.cpp | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
index d533762340d1c6..fdee8b71e5d983 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/no_unique_address.compile.pass.cpp
@@ -11,6 +11,8 @@
// XFAIL: msvc
// test [[no_unique_address]] is applied to the union
+// In particular, we ensure that we reuse tail padding in the T
+// to store the discriminator whenever we can.
#include <__type_traits/datasizeof.h>
#include <expected>
>From e37d5d8cfa009e69b8dbf9b2615148d7e615b44b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 19:05:20 +0100
Subject: [PATCH 47/55] add comment to
__conditional_no_unique_address_invoke_tag
---
libcxx/include/__expected/expected.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 52cc1dc38f5a05..205130fa11448a 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -88,6 +88,12 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) {
# endif
}
+// If parameter type `_Tp` of `__conditional_no_unique_address` is neither
+// copyable nor movable, a constructor with this tag is provided. For that
+// constructor, the user has to provide a function and arguments. The function
+// must return an object of type `_Tp`. When the function is invoked by the
+// constructor, guaranteed copy elision kicks in and the `_Tp` is constructed
+// in place.
struct __conditional_no_unique_address_invoke_tag {};
// This class implements an object with `[[no_unique_address]]` conditionally applied to it,
>From c46e26f416b135cac400fb7d5cb315bf97b32091 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 19:23:15 +0100
Subject: [PATCH 48/55] add a comment to the __repr constructor that calls
__make_union
---
libcxx/include/__expected/expected.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 205130fa11448a..fe132b2d4cdde0 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -284,6 +284,11 @@ class __expected_base {
_Args&&... __args)
: __union_(in_place, __tag, std::forward<_Args>(__args)...), __has_val_(false) {}
+ // The return value of `__make_union` must be constructed in place in the
+ // `__v` member of `__union_`, relying on guaranteed copy elision. To do
+ // this, the `__conditional_no_unique_address_invoke_tag` constructor is
+ // called with a lambda that is immediately called inside
+ // `__conditional_no_unique_address`'s constructor.
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
requires(!__put_flag_in_tail)
>From a5ad48f316d23682253047c979a885387b009681 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Fri, 19 Jan 2024 19:46:32 +0100
Subject: [PATCH 49/55] add comment to __destroy_union
---
libcxx/include/__expected/expected.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index fe132b2d4cdde0..e96d06cfa35322 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -323,6 +323,8 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
requires(!__put_flag_in_tail && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
{
+ // Note: Since the destructor of the union is trivial, this does nothing
+ // except to end the lifetime of the union.
std::destroy_at(&__union_.__v);
}
>From bd65b2a8d97b06b08eae7d1f706ee2c503f04f81 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 20 Jan 2024 12:10:54 +0100
Subject: [PATCH 50/55] introduce bool __allow_reusing_expected_tail_padding as
negation of __put_flag_in_tail for better readability
---
libcxx/include/__expected/expected.h | 36 +++++++++++++++-------------
1 file changed, 20 insertions(+), 16 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index e96d06cfa35322..893f838db3ee7c 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -261,7 +261,8 @@ class __expected_base {
_LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
- static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
+ static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
+ static constexpr bool __allow_reusing_expected_tail_padding = !__put_flag_in_tail;
struct __repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
@@ -291,7 +292,7 @@ class __expected_base {
// `__conditional_no_unique_address`'s constructor.
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
: __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -321,7 +322,8 @@ class __expected_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__put_flag_in_tail && (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
+ requires(__allow_reusing_expected_tail_padding &&
+ (is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>))
{
// Note: Since the destructor of the union is trivial, this does nothing
// except to end the lifetime of the union.
@@ -329,7 +331,8 @@ class __expected_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__put_flag_in_tail && (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
+ requires(__allow_reusing_expected_tail_padding &&
+ (!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>))
{
__destroy_union_member();
std::destroy_at(&__union_.__v);
@@ -337,7 +340,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t, _Args&&... __args)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
std::construct_at(&__union_.__v, in_place, std::forward<_Args>(__args)...);
__has_val_ = true;
@@ -345,7 +348,7 @@ class __expected_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
__has_val_ = false;
@@ -367,7 +370,7 @@ class __expected_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
if (__has_val)
return __union_t(in_place, std::forward<_OtherUnion>(__other).__val_);
@@ -443,7 +446,7 @@ class __expected_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__put_flag_in_tail, __repr> __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__allow_reusing_expected_tail_padding, __repr> __repr_;
};
template <class _Tp, class _Err>
@@ -1201,7 +1204,8 @@ class __expected_void_base {
_LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_;
};
- static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
+ static constexpr bool __put_flag_in_tail = __fits_in_tail_padding<__union_t, bool>;
+ static constexpr bool __allow_reusing_expected_tail_padding = !__put_flag_in_tail;
struct __repr {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr() = delete;
@@ -1220,7 +1224,7 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI constexpr explicit __repr(bool __has_val, _OtherUnion&& __other)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
: __union_(__conditional_no_unique_address_invoke_tag{},
[&] { return __make_union(__has_val, std::forward<_OtherUnion>(__other)); }),
__has_val_(__has_val) {}
@@ -1248,20 +1252,20 @@ class __expected_void_base {
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__put_flag_in_tail && is_trivially_destructible_v<_Err>)
+ requires(__allow_reusing_expected_tail_padding && is_trivially_destructible_v<_Err>)
{
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __destroy_union()
- requires(!__put_flag_in_tail && !is_trivially_destructible_v<_Err>)
+ requires(__allow_reusing_expected_tail_padding && !is_trivially_destructible_v<_Err>)
{
__destroy_union_member();
std::destroy_at(&__union_.__v);
}
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(in_place_t)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
std::construct_at(&__union_.__v, in_place);
__has_val_ = true;
@@ -1269,7 +1273,7 @@ class __expected_void_base {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI constexpr void __construct_union(unexpect_t, _Args&&... __args)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
std::construct_at(&__union_.__v, unexpect, std::forward<_Args>(__args)...);
__has_val_ = false;
@@ -1288,7 +1292,7 @@ class __expected_void_base {
template <class _OtherUnion>
_LIBCPP_HIDE_FROM_ABI static constexpr __union_t __make_union(bool __has_val, _OtherUnion&& __other)
- requires(!__put_flag_in_tail)
+ requires(__allow_reusing_expected_tail_padding)
{
if (__has_val)
return __union_t(in_place);
@@ -1343,7 +1347,7 @@ class __expected_void_base {
_LIBCPP_HIDE_FROM_ABI constexpr const _Err& __unex() const { return __repr_.__v.__union_.__v.__unex_; }
private:
- _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<!__put_flag_in_tail, __repr> __repr_;
+ _LIBCPP_NO_UNIQUE_ADDRESS __conditional_no_unique_address<__allow_reusing_expected_tail_padding, __repr> __repr_;
};
template <class _Tp, class _Err>
>From b5a179824312791b9bb5d7e9e70413feb45ea2e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 20 Jan 2024 12:14:08 +0100
Subject: [PATCH 51/55] use
put_flag_in_tail/allow_reusing_expected_tail_padding in synopsis
---
libcxx/include/__expected/expected.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 893f838db3ee7c..689de14e165360 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -193,12 +193,15 @@ inline constexpr bool __fits_in_tail_padding = []() {
// [[no_unique_address]] Err unex;
// };
//
+// static constexpr bool put_flag_in_tail = fits_in_tail_padding<union_t, bool>;
+// static constexpr bool allow_reusing_expected_tail_padding = !put_flag_in_tail;
+//
// struct repr {
// private:
// // If "has value" fits into the tail, this should be
// // `[[no_unique_address]]`, otherwise not.
// [[no_unique_address]] conditional_no_unique_address<
-// fits_in_tail_padding<union_t, bool>,
+// put_flag_in_tail,
// union_t>::type union_;
// [[no_unique_address]] bool has_val_;
// };
@@ -208,7 +211,7 @@ inline constexpr bool __fits_in_tail_padding = []() {
// // `[[no_unique_address]]` so that we fill out the
// // complete `expected` object.
// [[no_unique_address]] conditional_no_unique_address<
-// !fits_in_tail_padding<union_t, bool>,
+// allow_reusing_expected_tail_padding,
// repr>::type repr_;
// };
//
>From 9664d71ec1b0e182e34b6a95a9513c36d10edb60 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sat, 20 Jan 2024 12:21:27 +0100
Subject: [PATCH 52/55] autoformat
---
libcxx/include/__expected/expected.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index 689de14e165360..443d9257dc598d 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -489,7 +489,7 @@ class expected : private __expected_base<_Tp, _Err> {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr expected(const expected& __other) noexcept(
- is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_constructible_v<_Tp> && is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
!(is_trivially_copy_constructible_v<_Tp> && is_trivially_copy_constructible_v<_Err>))
: __base(__other.__has_val(), __other.__union()) {}
@@ -500,7 +500,7 @@ class expected : private __expected_base<_Tp, _Err> {
= default;
_LIBCPP_HIDE_FROM_ABI constexpr expected(expected&& __other) noexcept(
- is_nothrow_move_constructible_v<_Tp>&& is_nothrow_move_constructible_v<_Err>)
+ is_nothrow_move_constructible_v<_Tp> && is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_constructible_v<_Err> &&
!(is_trivially_move_constructible_v<_Tp> && is_trivially_move_constructible_v<_Err>))
: __base(__other.__has_val(), std::move(__other.__union())) {}
@@ -541,15 +541,15 @@ class expected : private __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<const _Up&, _Tp> ||
!is_convertible_v<const _OtherErr&, _Err>)
expected(const expected<_Up, _OtherErr>& __other) noexcept(
- is_nothrow_constructible_v<_Tp, const _Up&>&&
- is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
+ is_nothrow_constructible_v<_Tp, const _Up&> &&
+ is_nothrow_constructible_v<_Err, const _OtherErr&>) // strengthened
: __base(__other.__has_val(), __other.__union()) {}
template <class _Up, class _OtherErr>
requires __can_convert<_Up, _OtherErr, _Up, _OtherErr>::value
_LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up, _Tp> || !is_convertible_v<_OtherErr, _Err>)
expected(expected<_Up, _OtherErr>&& __other) noexcept(
- is_nothrow_constructible_v<_Tp, _Up>&& is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
+ is_nothrow_constructible_v<_Tp, _Up> && is_nothrow_constructible_v<_Err, _OtherErr>) // strengthened
: __base(__other.__has_val(), std::move(__other.__union())) {}
template <class _Up = _Tp>
@@ -628,8 +628,8 @@ class expected : private __expected_base<_Tp, _Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected& __rhs) noexcept(
- is_nothrow_copy_assignable_v<_Tp>&& is_nothrow_copy_constructible_v<_Tp>&& is_nothrow_copy_assignable_v<_Err>&&
- is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_assignable_v<_Tp> && is_nothrow_copy_constructible_v<_Tp> && is_nothrow_copy_assignable_v<_Err> &&
+ is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Tp> && is_copy_constructible_v<_Tp> && is_copy_assignable_v<_Err> &&
is_copy_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -647,8 +647,8 @@ class expected : private __expected_base<_Tp, _Err> {
}
_LIBCPP_HIDE_FROM_ABI constexpr expected&
- operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Tp>&& is_nothrow_move_constructible_v<_Tp>&&
- is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
+ operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Tp> && is_nothrow_move_constructible_v<_Tp> &&
+ is_nothrow_move_assignable_v<_Err> && is_nothrow_move_constructible_v<_Err>)
requires(is_move_constructible_v<_Tp> && is_move_assignable_v<_Tp> && is_move_constructible_v<_Err> &&
is_move_assignable_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -732,8 +732,8 @@ class expected : private __expected_base<_Tp, _Err> {
public:
// [expected.object.swap], swap
_LIBCPP_HIDE_FROM_ABI constexpr void
- swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Tp>&& is_nothrow_swappable_v<_Tp>&&
- is_nothrow_move_constructible_v<_Err>&& is_nothrow_swappable_v<_Err>)
+ swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Tp> && is_nothrow_swappable_v<_Tp> &&
+ is_nothrow_move_constructible_v<_Err> && is_nothrow_swappable_v<_Err>)
requires(is_swappable_v<_Tp> && is_swappable_v<_Err> && is_move_constructible_v<_Tp> &&
is_move_constructible_v<_Err> &&
(is_nothrow_move_constructible_v<_Tp> || is_nothrow_move_constructible_v<_Err>))
@@ -1477,7 +1477,7 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(const expected& __rhs) noexcept(
- is_nothrow_copy_assignable_v<_Err>&& is_nothrow_copy_constructible_v<_Err>) // strengthened
+ is_nothrow_copy_assignable_v<_Err> && is_nothrow_copy_constructible_v<_Err>) // strengthened
requires(is_copy_assignable_v<_Err> && is_copy_constructible_v<_Err>)
{
if (this->__has_val()) {
@@ -1497,7 +1497,7 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
_LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(expected&&) = delete;
_LIBCPP_HIDE_FROM_ABI constexpr expected&
- operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err>&& is_nothrow_move_constructible_v<_Err>)
+ operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err> && is_nothrow_move_constructible_v<_Err>)
requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)
{
if (this->__has_val()) {
@@ -1544,7 +1544,7 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
// [expected.void.swap], swap
_LIBCPP_HIDE_FROM_ABI constexpr void
- swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Err>&& is_nothrow_swappable_v<_Err>)
+ swap(expected& __rhs) noexcept(is_nothrow_move_constructible_v<_Err> && is_nothrow_swappable_v<_Err>)
requires(is_swappable_v<_Err> && is_move_constructible_v<_Err>)
{
auto __swap_val_unex_impl = [](expected& __with_val, expected& __with_err) {
>From e82f622c950b9361e2be41c56f09ef718c77495b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Sun, 21 Jan 2024 05:40:07 +0100
Subject: [PATCH 53/55] add 'XFAIL: msvc' to
expected.void/transform_error.mandates.verify.cpp test
---
.../expected.void/transform_error.mandates.verify.cpp | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
index 5f3b0be0fb627b..4f4f5839361e2a 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
@@ -12,6 +12,10 @@
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// With clang-cl, some warnings have a 'which is a Microsoft extension' suffix
+// which break the tests.
+// XFAIL: msvc
+
// Test the mandates
// template<class F> constexpr auto transform_error(F&& f) &;
>From f4df3f9daf9f9260a219ced85883bab185f623f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kokem=C3=BCller?= <jan.kokemueller at gmail.com>
Date: Mon, 22 Jan 2024 06:10:05 +0100
Subject: [PATCH 54/55] use 'XFAIL: gcc-13' instead of 'XFAIL: gcc'
---
.../expected/expected.expected/monadic/transform.pass.cpp | 2 +-
.../expected/expected.expected/monadic/transform_error.pass.cpp | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
index 424295bffdf2a2..d38a46f0452485 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform.pass.cpp
@@ -10,7 +10,7 @@
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333
-// XFAIL: gcc
+// XFAIL: gcc-13
// <expected>
diff --git a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
index 23bf6783a14b1d..ec55f637f02020 100644
--- a/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
+++ b/libcxx/test/std/utilities/expected/expected.expected/monadic/transform_error.pass.cpp
@@ -10,7 +10,7 @@
// GCC has a issue for `Guaranteed copy elision for potentially-overlapping non-static data members`,
// please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108333.
-// XFAIL: gcc
+// XFAIL: gcc-13
// <expected>
>From 89290d5cbd801b43f1e30fc26d531f5da6d25ef3 Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Mon, 22 Jan 2024 08:49:44 -0500
Subject: [PATCH 55/55] Add release note
---
libcxx/docs/ReleaseNotes/18.rst | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index 311a06e34c49d2..8044584919f60e 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -219,6 +219,28 @@ ABI Affecting Changes
should not be a major problem for most users. However it is probably worth auditing ranges-heavy code for ABI boundaries that
would contain these views, or for types that contain these views as members and which are passed across ABI boundaries.
+- The amount of padding bytes available for use at the end of certain ``std::expected`` instantiations has changed in this
+ release. This is an ABI break for any code that held a ``std::expected`` member with ``[[no_unique_address]]`` in an
+ ABI-facing type. In those cases, the layout of the enclosing type will change, breaking the ABI. However, the
+ ``std::expected<T, E>`` member requires a few characteristics in order to be affected by this change:
+
+ - A type equivalent to ``union {T ; E}`` needs to have more than one byte of padding available.
+ - The ``std::expected<T, E>`` member must have been in a situation where its padding bytes were previously reused by
+ another object, which can happen in a few cases (this is probably not exhaustive):
+
+ - It is a member with ``[[no_unique_address]]`` applied to it, and it is followed by another data member, or
+ - It is a member with ``[[no_unique_address]]`` applied to it, and it is the last member of the user-defined type,
+ and that user-defined type is used in ways that its padding bytes can be reused, or
+ - It is inherited from
+
+ We expect that this will not be a very frequent occurrence. However, there is unfortunately no technique we can use
+ in the library to catch such misuse. Indeed, even applying an ABI tag to ``std::expected`` would not help since ABI
+ tags are not propagated to containing types. As a result, if you notice very difficult to explain bugs around the
+ usage of a ``std::expected``, you should consider checking whether you are hitting this ABI break. This change was
+ done to fix `#70494 <https://github.com/llvm/llvm-project/issues/70494>`_ and the vendor communication is handled
+ in `#70820 <https://github.com/llvm/llvm-project/issues/70820>`_.
+
+
Build System Changes
--------------------
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