| //===----------------------------------------------------------------------===// |
| // |
| // 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_SAME_H |
| #define _LIBCPP___TYPE_TRAITS_IS_SAME_H |
| |
| #include <__config> |
| #include <__type_traits/integral_constant.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _Tp, class _Up> |
| struct _LIBCPP_TEMPLATE_VIS is_same : _BoolConstant<__is_same(_Tp, _Up)> { }; |
| |
| #if _LIBCPP_STD_VER > 14 |
| template <class _Tp, class _Up> |
| inline constexpr bool is_same_v = __is_same(_Tp, _Up); |
| #endif |
| |
| // _IsSame<T,U> has the same effect as is_same<T,U> but instantiates fewer types: |
| // is_same<A,B> and is_same<C,D> are guaranteed to be different types, but |
| // _IsSame<A,B> and _IsSame<C,D> are the same type (namely, false_type). |
| // Neither GCC nor Clang can mangle the __is_same builtin, so _IsSame |
| // mustn't be directly used anywhere that contributes to name-mangling |
| // (such as in a dependent return type). |
| |
| template <class _Tp, class _Up> |
| using _IsSame = _BoolConstant<__is_same(_Tp, _Up)>; |
| |
| template <class _Tp, class _Up> |
| using _IsNotSame = _BoolConstant<!__is_same(_Tp, _Up)>; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___TYPE_TRAITS_IS_SAME_H |