[libcxx-commits] [libcxx] c99a585 - [libc++] Make C++03 reference_wrapper more like C++11.
Arthur O'Dwyer via libcxx-commits
libcxx-commits at lists.llvm.org
Wed Jan 26 16:37:46 PST 2022
Author: Arthur O'Dwyer
Date: 2022-01-26T19:34:03-05:00
New Revision: c99a585399381dd7d7391d2d93e9a2cbdf59d955
URL: https://github.com/llvm/llvm-project/commit/c99a585399381dd7d7391d2d93e9a2cbdf59d955
DIFF: https://github.com/llvm/llvm-project/commit/c99a585399381dd7d7391d2d93e9a2cbdf59d955.diff
LOG: [libc++] Make C++03 reference_wrapper more like C++11.
Remove a bunch of LIBCPP_CXX03_LANG. This is the result of a
rabbithole to re-eliminate the workaround I introduced into
std::cref in D117953. It turns out that Clang's C++03 mode
(the only compiler we care about C++03 for) now supports all
the things we were originally eschewing via LIBCPP_CXX03_LANG;
we can fully support these reference_wrapper features in
C++03 mode, and un-XFAIL the relevant tests.
Drive-by constexprify a few more tests.
Differential Revision: https://reviews.llvm.org/D117974
Added:
Modified:
libcxx/include/__functional/reference_wrapper.h
libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp
libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor2.pass.cpp
libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_ctor.compile.fail.cpp
libcxx/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_1.compile.fail.cpp
Removed:
################################################################################
diff --git a/libcxx/include/__functional/reference_wrapper.h b/libcxx/include/__functional/reference_wrapper.h
index c5de5e5f2e8df..d04d51568beb3 100644
--- a/libcxx/include/__functional/reference_wrapper.h
+++ b/libcxx/include/__functional/reference_wrapper.h
@@ -34,25 +34,16 @@ class _LIBCPP_TEMPLATE_VIS reference_wrapper
private:
type* __f_;
-#ifndef _LIBCPP_CXX03_LANG
static void __fun(_Tp&) _NOEXCEPT;
static void __fun(_Tp&&) = delete;
-#endif
public:
- // construct/copy/destroy
-#ifdef _LIBCPP_CXX03_LANG
- _LIBCPP_INLINE_VISIBILITY
- reference_wrapper(type& __f) _NOEXCEPT
- : __f_(_VSTD::addressof(__f)) {}
-#else
- template <class _Up, class = __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, decltype(__fun(declval<_Up>())) >>
+ template <class _Up, class = __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, decltype(__fun(declval<_Up>())) > >
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
reference_wrapper(_Up&& __u) _NOEXCEPT_(noexcept(__fun(declval<_Up>()))) {
type& __f = static_cast<_Up&&>(__u);
__f_ = _VSTD::addressof(__f);
}
-#endif
// access
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
@@ -210,15 +201,11 @@ inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
reference_wrapper<const _Tp>
cref(reference_wrapper<_Tp> __t) _NOEXCEPT
{
- // C++20 says "return __t", but C++03 lacks the relevant
- // converting constructor. This should be equivalent.
- return __t.get();
+ return __t;
}
-#ifndef _LIBCPP_CXX03_LANG
template <class _Tp> void ref(const _Tp&&) = delete;
template <class _Tp> void cref(const _Tp&&) = delete;
-#endif
_LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp
index be9261a5c55c2..2759b921fabe0 100644
--- a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp
+++ b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp
@@ -6,8 +6,6 @@
//
//===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03
-
// <functional>
//
// reference_wrapper
@@ -21,65 +19,58 @@
#include "test_macros.h"
struct convertible_to_int_ref {
- int val = 0;
- operator int&() { return val; }
- operator int const&() const { return val; }
+ int val = 0;
+ operator int&() { return val; }
+ operator int const&() const { return val; }
};
template <bool IsNothrow>
struct nothrow_convertible {
- int val = 0;
- operator int&() noexcept(IsNothrow) { return val; }
+ int val = 0;
+ operator int&() TEST_NOEXCEPT_COND(IsNothrow) { return val; }
};
struct convertible_from_int {
- convertible_from_int(int) {}
+ convertible_from_int(int) {}
};
void meow(std::reference_wrapper<int>) {}
void meow(convertible_from_int) {}
-int gi;
-std::reference_wrapper<int> purr() { return gi; };
-
-template <class T>
-void
-test(T& t)
-{
- std::reference_wrapper<T> r(t);
- assert(&r.get() == &t);
-}
-
-void f() {}
-
int main(int, char**)
{
- convertible_to_int_ref convi;
- test(convi);
- convertible_to_int_ref const convic;
- test(convic);
-
- {
+ {
+ convertible_to_int_ref t;
+ std::reference_wrapper<convertible_to_int_ref> r(t);
+ assert(&r.get() == &t);
+ }
+ {
+ const convertible_to_int_ref t;
+ std::reference_wrapper<const convertible_to_int_ref> r(t);
+ assert(&r.get() == &t);
+ }
+ {
using Ref = std::reference_wrapper<int>;
- static_assert((std::is_nothrow_constructible<Ref, nothrow_convertible<true>>::value), "");
- static_assert((!std::is_nothrow_constructible<Ref, nothrow_convertible<false>>::value), "");
- }
-
- {
+ ASSERT_NOEXCEPT(Ref(nothrow_convertible<true>()));
+ ASSERT_NOT_NOEXCEPT(Ref(nothrow_convertible<false>()));
+ }
+ {
meow(0);
- (true) ? purr() : 0;
- }
-
-#if TEST_STD_VER >= 17
- {
+ }
+ {
+ extern std::reference_wrapper<int> purr();
+ ASSERT_SAME_TYPE(decltype(true ? purr() : 0), int);
+ }
+#if TEST_STD_VER > 14
+ {
int i = 0;
std::reference_wrapper ri(i);
static_assert((std::is_same<decltype(ri), std::reference_wrapper<int>>::value), "" );
const int j = 0;
std::reference_wrapper rj(j);
static_assert((std::is_same<decltype(rj), std::reference_wrapper<const int>>::value), "" );
- }
+ }
#endif
- return 0;
+ return 0;
}
diff --git a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor2.pass.cpp b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor2.pass.cpp
index 30d7cdb4a38b4..0ef87ade87c9d 100644
--- a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor2.pass.cpp
+++ b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor2.pass.cpp
@@ -6,8 +6,6 @@
//
//===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03
-
// <functional>
//
// reference_wrapper
@@ -20,46 +18,48 @@
#include "test_macros.h"
-struct B {} b;
+struct B {};
struct A1 {
- operator B& () const { return b; }
+ mutable B b_;
+ TEST_CONSTEXPR operator B&() const { return b_; }
};
+
struct A2 {
- operator B& () const noexcept { return b; }
+ mutable B b_;
+ TEST_CONSTEXPR operator B&() const TEST_NOEXCEPT { return b_; }
};
-int main(int, char**)
-{
- {
- std::reference_wrapper<B> b1 = A1();
- assert(&b1.get() == &b);
- b1 = A1();
- assert(&b1.get() == &b);
+void implicitly_convert(std::reference_wrapper<B>) TEST_NOEXCEPT;
- static_assert(std::is_convertible<A1, std::reference_wrapper<B>>::value, "");
- static_assert(!std::is_nothrow_constructible<std::reference_wrapper<B>, A1>::value, "");
-#if TEST_STD_VER >= 20
- static_assert(!std::is_nothrow_convertible_v<A1, std::reference_wrapper<B>>);
-#endif
- static_assert(std::is_assignable<std::reference_wrapper<B>, A1>::value, "");
- static_assert(!std::is_nothrow_assignable<std::reference_wrapper<B>, A1>::value, "");
- }
-
- {
- std::reference_wrapper<B> b2 = A2();
- assert(&b2.get() == &b);
- b2 = A2();
- assert(&b2.get() == &b);
+TEST_CONSTEXPR_CXX20 bool test()
+{
+ {
+ A1 a;
+ ASSERT_NOT_NOEXCEPT(implicitly_convert(a));
+ std::reference_wrapper<B> b1 = a;
+ assert(&b1.get() == &a.b_);
+ ASSERT_NOT_NOEXCEPT(b1 = a);
+ b1 = a;
+ assert(&b1.get() == &a.b_);
+ }
+ {
+ A2 a;
+ ASSERT_NOEXCEPT(implicitly_convert(a));
+ std::reference_wrapper<B> b2 = a;
+ assert(&b2.get() == &a.b_);
+ ASSERT_NOEXCEPT(b2 = a);
+ b2 = a;
+ assert(&b2.get() == &a.b_);
+ }
+ return true;
+}
- static_assert(std::is_convertible<A2, std::reference_wrapper<B>>::value, "");
- static_assert(std::is_nothrow_constructible<std::reference_wrapper<B>, A2>::value, "");
-#if TEST_STD_VER >= 20
- static_assert(std::is_nothrow_convertible_v<A2, std::reference_wrapper<B>>);
+int main(int, char**) {
+ test();
+#if TEST_STD_VER > 17
+ static_assert(test());
#endif
- static_assert(std::is_assignable<std::reference_wrapper<B>, A2>::value, "");
- static_assert(std::is_nothrow_assignable<std::reference_wrapper<B>, A2>::value, "");
- }
- return 0;
+ return 0;
}
diff --git a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_ctor.compile.fail.cpp b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_ctor.compile.fail.cpp
index c067dd942a542..b9792105046d5 100644
--- a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_ctor.compile.fail.cpp
+++ b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_ctor.compile.fail.cpp
@@ -12,8 +12,6 @@
// reference_wrapper(T&&) = delete;
-// XFAIL: c++03
-
#include <functional>
#include <cassert>
diff --git a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_1.compile.fail.cpp b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_1.compile.fail.cpp
index 9f45b94e828f8..3721b9bd47f87 100644
--- a/libcxx/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_1.compile.fail.cpp
+++ b/libcxx/test/std/utilities/function.objects/refwrap/refwrap.helpers/ref_1.compile.fail.cpp
@@ -14,8 +14,6 @@
// Don't allow binding to a temp
-// XFAIL: c++03
-
#include <functional>
struct A {};
More information about the libcxx-commits
mailing list