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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-11-10 01:30:45 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-11-10 01:59:34 +0000 |
| commit | 0cbb756fe9c8e13a743bdcf599481b31bd01ddbc (patch) | |
| tree | 2a41cb67dad91858a7cdf29b722537638087a0eb | |
| parent | 1cdfd0e5cd5fc1f493d0832ed65d31320f9585b7 (diff) | |
| download | gcc-0cbb756fe9c8e13a743bdcf599481b31bd01ddbc.zip gcc-0cbb756fe9c8e13a743bdcf599481b31bd01ddbc.tar.gz gcc-0cbb756fe9c8e13a743bdcf599481b31bd01ddbc.tar.bz2 | |
libstdc++: Optimize std::destructible concept
This uses variable templates and constraints to define a much simpler
std::destructible concept. This avoids instantiating the trait
std::is_nothrow_destructible and all its implementation in terms of
__is_destructible_safe and __is_destructible_impl.
If we had an intrinsic we could just use that (PR c++/107600).
libstdc++-v3/ChangeLog:
* include/std/concepts (__detail::__destructible_impl)
(__detail::__destructible): New variable templates.
(destructible): Use __detail::__destructible.
* testsuite/std/concepts/concepts.lang/concept.destructible/1.cc:
Add more checks for array and reference types.
| -rw-r--r-- | libstdc++-v3/include/std/concepts | 24 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.destructible/1.cc | 5 |
2 files changed, 25 insertions, 4 deletions
diff --git a/libstdc++-v3/include/std/concepts b/libstdc++-v3/include/std/concepts index 3213906..c062d62 100644 --- a/libstdc++-v3/include/std/concepts +++ b/libstdc++-v3/include/std/concepts @@ -113,9 +113,25 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Tp> using __cref = const remove_reference_t<_Tp>&; - template<typename _Tp> - concept __class_or_enum - = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>; + template<typename _Tp> + concept __class_or_enum + = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>; + + template<typename _Tp> + constexpr bool __destructible_impl = false; + template<typename _Tp> + requires requires(_Tp& __t) { { __t.~_Tp() } noexcept; } + constexpr bool __destructible_impl<_Tp> = true; + + template<typename _Tp> + constexpr bool __destructible = __destructible_impl<_Tp>; + template<typename _Tp> + constexpr bool __destructible<_Tp&> = true; + template<typename _Tp> + constexpr bool __destructible<_Tp&&> = true; + template<typename _Tp, size_t _Nm> + constexpr bool __destructible<_Tp[_Nm]> = __destructible<_Tp>; + } // namespace __detail /// [concept.assignable], concept assignable_from @@ -129,7 +145,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION /// [concept.destructible], concept destructible template<typename _Tp> - concept destructible = is_nothrow_destructible_v<_Tp>; + concept destructible = __detail::__destructible<_Tp>; /// [concept.constructible], concept constructible_from template<typename _Tp, typename... _Args> diff --git a/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.destructible/1.cc b/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.destructible/1.cc index a0bd036..81d72ab 100644 --- a/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.destructible/1.cc +++ b/libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.destructible/1.cc @@ -29,6 +29,7 @@ static_assert( std::destructible<int&&> ); static_assert( std::destructible<const int&> ); static_assert( !std::destructible<int[]> ); static_assert( std::destructible<int[2]> ); +static_assert( std::destructible<int[2][3]> ); static_assert( !std::destructible<int()> ); static_assert( std::destructible<int(*)()> ); static_assert( std::destructible<int(&)()> ); @@ -47,6 +48,8 @@ struct C ~C() noexcept(false) { } }; static_assert( !std::destructible<C> ); +static_assert( std::destructible<C&> ); +static_assert( !std::destructible<C[1]> ); class D { public: @@ -55,3 +58,5 @@ private: ~D() { } }; static_assert( !std::destructible<D> ); +static_assert( std::destructible<D&> ); +static_assert( !std::destructible<D[1]> ); |