[libcxx-commits] [libcxx] 170810f - P1957R2: remove special-case for booleans in std::variant (#71502)
via libcxx-commits
libcxx-commits at lists.llvm.org
Wed Nov 15 14:51:02 PST 2023
Author: David Benjamin
Date: 2023-11-15T23:50:58+01:00
New Revision: 170810fca6ee0f0e9a5b60c83122127d68bcc7ec
URL: https://github.com/llvm/llvm-project/commit/170810fca6ee0f0e9a5b60c83122127d68bcc7ec
DIFF: https://github.com/llvm/llvm-project/commit/170810fca6ee0f0e9a5b60c83122127d68bcc7ec.diff
LOG: P1957R2: remove special-case for booleans in std::variant (#71502)
This picks up the std::variant half of P1957R2. Fixes #62332.
Added:
Modified:
libcxx/docs/Status/Cxx20Papers.csv
libcxx/include/variant
libcxx/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
libcxx/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
Removed:
################################################################################
diff --git a/libcxx/docs/Status/Cxx20Papers.csv b/libcxx/docs/Status/Cxx20Papers.csv
index 107b2bca110f692..07f53ee995ea16b 100644
--- a/libcxx/docs/Status/Cxx20Papers.csv
+++ b/libcxx/docs/Status/Cxx20Papers.csv
@@ -173,7 +173,7 @@
"`P1868R2 <https://wg21.link/P1868R2>`__","LWG","width: clarifying units of width and precision in std::format","Prague","|Complete|","14.0"
"`P1937R2 <https://wg21.link/P1937R2>`__","CWG","Fixing inconsistencies between constexpr and consteval functions","Prague","* *",""
"`P1956R1 <https://wg21.link/P1956R1>`__","LWG","On the names of low-level bit manipulation functions","Prague","|Complete|","12.0"
-"`P1957R2 <https://wg21.link/P1957R2>`__","CWG","Converting from ``T*``\ to bool should be considered narrowing (re: US 212)","Prague","* *",""
+"`P1957R2 <https://wg21.link/P1957R2>`__","CWG","Converting from ``T*``\ to bool should be considered narrowing (re: US 212)","Prague","|Complete|","18.0"
"`P1963R0 <https://wg21.link/P1963R0>`__","LWG","Fixing US 313","Prague","* *","",""
"`P1964R2 <https://wg21.link/P1964R2>`__","LWG","Wording for boolean-testable","Prague","|Complete|","13.0"
"`P1970R2 <https://wg21.link/P1970R2>`__","LWG","Consistency for size() functions: Add ranges::ssize","Prague","|Complete|","15.0","|ranges|"
diff --git a/libcxx/include/variant b/libcxx/include/variant
index 7df2e87cf3bf986..d89c0596b1db0de 100644
--- a/libcxx/include/variant
+++ b/libcxx/include/variant
@@ -1252,22 +1252,6 @@ struct __overload {
auto operator()(_Tp, _Up&&) const -> __check_for_narrowing<_Tp, _Up>;
};
-template <class _Tp, size_t>
-struct __overload_bool {
- template <class _Up, class _Ap = __remove_cvref_t<_Up>>
- auto operator()(bool, _Up&&) const
- -> enable_if_t<is_same_v<_Ap, bool>, __type_identity<_Tp>>;
-};
-
-template <size_t _Idx>
-struct __overload<bool, _Idx> : __overload_bool<bool, _Idx> {};
-template <size_t _Idx>
-struct __overload<bool const, _Idx> : __overload_bool<bool const, _Idx> {};
-template <size_t _Idx>
-struct __overload<bool volatile, _Idx> : __overload_bool<bool volatile, _Idx> {};
-template <size_t _Idx>
-struct __overload<bool const volatile, _Idx> : __overload_bool<bool const volatile, _Idx> {};
-
template <class ..._Bases>
struct __all_overloads : _Bases... {
void operator()() const;
diff --git a/libcxx/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp b/libcxx/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
index 0cab5689114360a..c63626090c2fe9a 100644
--- a/libcxx/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
+++ b/libcxx/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
@@ -19,6 +19,7 @@
#include <string>
#include <type_traits>
#include <variant>
+#include <vector>
#include <memory>
#include "test_macros.h"
@@ -145,8 +146,8 @@ void test_T_assignment_sfinae() {
};
static_assert(!std::is_assignable<V, X>::value,
"no boolean conversion in operator=");
- static_assert(!std::is_assignable<V, std::false_type>::value,
- "no converted to bool in operator=");
+ static_assert(std::is_assignable<V, std::false_type>::value,
+ "converted to bool in operator=");
}
{
struct X {};
@@ -295,12 +296,21 @@ void test_T_assignment_performs_assignment() {
#endif // TEST_HAS_NO_EXCEPTIONS
}
+void test_T_assignment_vector_bool() {
+ std::vector<bool> vec = {true};
+ std::variant<bool, int> v;
+ v = vec[0];
+ assert(v.index() == 0);
+ assert(std::get<0>(v) == true);
+}
+
int main(int, char**) {
test_T_assignment_basic();
test_T_assignment_performs_construction();
test_T_assignment_performs_assignment();
test_T_assignment_noexcept();
test_T_assignment_sfinae();
+ test_T_assignment_vector_bool();
return 0;
}
diff --git a/libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp b/libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
index 5c1bf2bbc00bcaf..d93d429e262c05b 100644
--- a/libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
+++ b/libcxx/test/std/utilities/variant/variant.variant/variant.assign/conv.pass.cpp
@@ -33,9 +33,8 @@ int main(int, char**)
static_assert(!std::is_assignable<std::variant<int, bool>, decltype("meow")>::value, "");
static_assert(!std::is_assignable<std::variant<int, const bool>, decltype("meow")>::value, "");
- static_assert(!std::is_assignable<std::variant<int, const volatile bool>, decltype("meow")>::value, "");
- static_assert(!std::is_assignable<std::variant<bool>, std::true_type>::value, "");
+ static_assert(std::is_assignable<std::variant<bool>, std::true_type>::value, "");
static_assert(!std::is_assignable<std::variant<bool>, std::unique_ptr<char> >::value, "");
static_assert(!std::is_assignable<std::variant<bool>, decltype(nullptr)>::value, "");
diff --git a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
index 5d3e8d884ee1ae3..04329f4f412b06a 100644
--- a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
+++ b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/T.pass.cpp
@@ -19,6 +19,7 @@
#include <type_traits>
#include <variant>
#include <memory>
+#include <vector>
#include "test_macros.h"
#include "variant_test_helpers.h"
@@ -79,8 +80,8 @@ void test_T_ctor_sfinae() {
};
static_assert(!std::is_constructible<V, X>::value,
"no boolean conversion in constructor");
- static_assert(!std::is_constructible<V, std::false_type>::value,
- "no converted to bool in constructor");
+ static_assert(std::is_constructible<V, std::false_type>::value,
+ "converted to bool in constructor");
}
{
struct X {};
@@ -138,12 +139,12 @@ void test_T_ctor_basic() {
assert(std::get<0>(v) == "foo");
}
{
- std::variant<bool volatile, std::unique_ptr<int>> v = nullptr;
+ std::variant<bool, std::unique_ptr<int>> v = nullptr;
assert(v.index() == 1);
assert(std::get<1>(v) == nullptr);
}
{
- std::variant<bool volatile const, int> v = true;
+ std::variant<bool const, int> v = true;
assert(v.index() == 0);
assert(std::get<0>(v));
}
@@ -198,11 +199,19 @@ void test_construction_with_repeated_types() {
static_assert(std::is_constructible<V, Bar>::value, "");
}
+void test_vector_bool() {
+ std::vector<bool> vec = {true};
+ std::variant<bool, int> v = vec[0];
+ assert(v.index() == 0);
+ assert(std::get<0>(v) == true);
+}
+
int main(int, char**) {
test_T_ctor_basic();
test_T_ctor_noexcept();
test_T_ctor_sfinae();
test_no_narrowing_check_for_class_types();
test_construction_with_repeated_types();
+ test_vector_bool();
return 0;
}
diff --git a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
index 152f694ce30f433..7a4c68b5dacca7f 100644
--- a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
+++ b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/conv.pass.cpp
@@ -32,9 +32,8 @@ int main(int, char**)
static_assert(!std::is_constructible<std::variant<int, bool>, decltype("meow")>::value, "");
static_assert(!std::is_constructible<std::variant<int, const bool>, decltype("meow")>::value, "");
- static_assert(!std::is_constructible<std::variant<int, const volatile bool>, decltype("meow")>::value, "");
- static_assert(!std::is_constructible<std::variant<bool>, std::true_type>::value, "");
+ static_assert(std::is_constructible<std::variant<bool>, std::true_type>::value, "");
static_assert(!std::is_constructible<std::variant<bool>, std::unique_ptr<char> >::value, "");
static_assert(!std::is_constructible<std::variant<bool>, decltype(nullptr)>::value, "");
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