| //===----------------------------------------------------------------------===// |
| // |
| // 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_ADD_LVALUE_REFERENCE_H |
| #define _LIBCPP___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H |
| |
| #include <__config> |
| #include <__type_traits/is_referenceable.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if __has_builtin(__add_lvalue_reference) |
| |
| template <class _Tp> |
| using __add_lvalue_reference_t = __add_lvalue_reference(_Tp); |
| |
| #else |
| |
| template <class _Tp, bool = __libcpp_is_referenceable<_Tp>::value> |
| struct __add_lvalue_reference_impl { |
| typedef _LIBCPP_NODEBUG _Tp type; |
| }; |
| template <class _Tp > |
| struct __add_lvalue_reference_impl<_Tp, true> { |
| typedef _LIBCPP_NODEBUG _Tp& type; |
| }; |
| |
| template <class _Tp> |
| using __add_lvalue_reference_t = typename __add_lvalue_reference_impl<_Tp>::type; |
| |
| #endif // __has_builtin(__add_lvalue_reference) |
| |
| template <class _Tp> |
| struct add_lvalue_reference { |
| using type _LIBCPP_NODEBUG = __add_lvalue_reference_t<_Tp>; |
| }; |
| |
| #if _LIBCPP_STD_VER > 11 |
| template <class _Tp> using add_lvalue_reference_t = __add_lvalue_reference_t<_Tp>; |
| #endif |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H |