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| author | Jonathan Wakely <jwakely@redhat.com> | 2023-11-22 15:09:24 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2024-01-07 00:58:45 +0000 |
| commit | 7af436ada243bbb6ae601c85bd47ea908c71fb41 (patch) | |
| tree | 0a09107e773d6fc29ec24280f2525c9d0c425f1a | |
| parent | b368d79998003c2e5657a91055cb27991988b44b (diff) | |
| download | gcc-7af436ada243bbb6ae601c85bd47ea908c71fb41.zip gcc-7af436ada243bbb6ae601c85bd47ea908c71fb41.tar.gz gcc-7af436ada243bbb6ae601c85bd47ea908c71fb41.tar.bz2 | |
libstdc++: Optimize std::is_trivially_destructible_v
This reduces the overhead of using std::is_trivially_destructible_v and
as a result fixes some recent regressions seen with a non-default
GLIBCXX_TESTSUITE_STDS env var:
FAIL: 20_util/variant/87619.cc -std=gnu++20 (test for excess errors)
FAIL: 20_util/variant/87619.cc -std=gnu++23 (test for excess errors)
FAIL: 20_util/variant/87619.cc -std=gnu++26 (test for excess errors)
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_trivially_destructible_v): Use
built-in directly when concepts are supported.
* testsuite/20_util/is_trivially_destructible/value_v.cc: New
test.
| -rw-r--r-- | libstdc++-v3/include/std/type_traits | 19 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/20_util/is_trivially_destructible/value_v.cc | 40 |
2 files changed, 59 insertions, 0 deletions
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 3b1b419..1cec082 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -3410,9 +3410,28 @@ template <typename _Tp> inline constexpr bool is_trivially_move_assignable_v = __is_trivially_assignable(__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>); + +#if __cpp_concepts +template <typename _Tp> + inline constexpr bool is_trivially_destructible_v = false; + +template <typename _Tp> + requires (!is_reference_v<_Tp>) && requires (_Tp& __t) { __t.~_Tp(); } + inline constexpr bool is_trivially_destructible_v<_Tp> + = __has_trivial_destructor(_Tp); +template <typename _Tp> + inline constexpr bool is_trivially_destructible_v<_Tp&> = true; +template <typename _Tp> + inline constexpr bool is_trivially_destructible_v<_Tp&&> = true; +template <typename _Tp, size_t _Nm> + inline constexpr bool is_trivially_destructible_v<_Tp[_Nm]> + = is_trivially_destructible_v<_Tp>; +#else template <typename _Tp> inline constexpr bool is_trivially_destructible_v = is_trivially_destructible<_Tp>::value; +#endif + template <typename _Tp, typename... _Args> inline constexpr bool is_nothrow_constructible_v = __is_nothrow_constructible(_Tp, _Args...); diff --git a/libstdc++-v3/testsuite/20_util/is_trivially_destructible/value_v.cc b/libstdc++-v3/testsuite/20_util/is_trivially_destructible/value_v.cc new file mode 100644 index 0000000..7db098a --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_trivially_destructible/value_v.cc @@ -0,0 +1,40 @@ +// { dg-do compile { target c++17 } } +#include <type_traits> +#include <testsuite_tr1.h> + +template<typename T> +constexpr void test_cv() +{ + static_assert(std::is_trivially_destructible_v<const T> + == std::is_trivially_destructible_v<T>); + static_assert(std::is_trivially_destructible_v<volatile T> + == std::is_trivially_destructible_v<T>); + static_assert(std::is_trivially_destructible_v<const volatile T> + == std::is_trivially_destructible_v<T>); +} + +template<typename T, bool Expected> +void test() +{ + static_assert(std::is_trivially_destructible_v<T> == Expected); + test_cv<T>(); +} + +void test01() +{ + using namespace __gnu_test; + + test<int, true>(); + test<int&, true>(); + test<int&&, true>(); + test<int[1], true>(); + test<TType, true>(); + test<TType[1], true>(); + test<PODType, true>(); + test<PODType[1], true>(); + test<NType, false>(); + test<SLType, false>(); + test<int(), false>(); + test<void, false>(); + test<int[], false>(); +} |