1 //===----------------------------------------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #ifndef _LIBCPP___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H
10 #define _LIBCPP___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H
13 #include <__type_traits/is_referenceable.h>
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 # pragma GCC system_header
19 _LIBCPP_BEGIN_NAMESPACE_STD
21 template <class _Tp, bool = __is_referenceable<_Tp>::value> struct __add_lvalue_reference_impl { typedef _LIBCPP_NODEBUG _Tp type; };
22 template <class _Tp > struct __add_lvalue_reference_impl<_Tp, true> { typedef _LIBCPP_NODEBUG _Tp& type; };
24 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_lvalue_reference
25 {typedef _LIBCPP_NODEBUG typename __add_lvalue_reference_impl<_Tp>::type type;};
27 #if _LIBCPP_STD_VER > 11
28 template <class _Tp> using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
31 _LIBCPP_END_NAMESPACE_STD
33 #endif // _LIBCPP___TYPE_TRAITS_ADD_LVALUE_REFERENCE_H