| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___TYPE_TRAITS_IS_DESTRUCTIBLE_H |
| #define _LIBCPP___TYPE_TRAITS_IS_DESTRUCTIBLE_H |
| |
| #include <__config> |
| #include <__type_traits/integral_constant.h> |
| #include <__type_traits/is_function.h> |
| #include <__type_traits/is_reference.h> |
| #include <__type_traits/remove_all_extents.h> |
| #include <__utility/declval.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if __has_builtin(__is_destructible) |
| |
| template<class _Tp> |
| struct _LIBCPP_TEMPLATE_VIS is_destructible : _BoolConstant<__is_destructible(_Tp)> { }; |
| |
| #if _LIBCPP_STD_VER >= 17 |
| template <class _Tp> |
| inline constexpr bool is_destructible_v = __is_destructible(_Tp); |
| #endif |
| |
| #else // __has_builtin(__is_destructible) |
| |
| // if it's a reference, return true |
| // if it's a function, return false |
| // if it's void, return false |
| // if it's an array of unknown bound, return false |
| // Otherwise, return "declval<_Up&>().~_Up()" is well-formed |
| // where _Up is remove_all_extents<_Tp>::type |
| |
| template <class> |
| struct __is_destructible_apply { typedef int type; }; |
| |
| template <typename _Tp> |
| struct __is_destructor_wellformed { |
| template <typename _Tp1> |
| static true_type __test ( |
| typename __is_destructible_apply<decltype(std::declval<_Tp1&>().~_Tp1())>::type |
| ); |
| |
| template <typename _Tp1> |
| static false_type __test (...); |
| |
| static const bool value = decltype(__test<_Tp>(12))::value; |
| }; |
| |
| template <class _Tp, bool> |
| struct __destructible_imp; |
| |
| template <class _Tp> |
| struct __destructible_imp<_Tp, false> |
| : public integral_constant<bool, |
| __is_destructor_wellformed<__remove_all_extents_t<_Tp> >::value> {}; |
| |
| template <class _Tp> |
| struct __destructible_imp<_Tp, true> |
| : public true_type {}; |
| |
| template <class _Tp, bool> |
| struct __destructible_false; |
| |
| template <class _Tp> |
| struct __destructible_false<_Tp, false> : public __destructible_imp<_Tp, is_reference<_Tp>::value> {}; |
| |
| template <class _Tp> |
| struct __destructible_false<_Tp, true> : public false_type {}; |
| |
| template <class _Tp> |
| struct is_destructible |
| : public __destructible_false<_Tp, is_function<_Tp>::value> {}; |
| |
| template <class _Tp> |
| struct is_destructible<_Tp[]> |
| : public false_type {}; |
| |
| template <> |
| struct is_destructible<void> |
| : public false_type {}; |
| |
| #if _LIBCPP_STD_VER >= 17 |
| template <class _Tp> |
| inline constexpr bool is_destructible_v = is_destructible<_Tp>::value; |
| #endif |
| |
| #endif // __has_builtin(__is_destructible) |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___TYPE_TRAITS_IS_DESTRUCTIBLE_H |