1 //===----------------------------------------------------------------------===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___TYPE_TRAITS_IS_REFERENCE_WRAPPER_H
10 #define _LIBCPP___TYPE_TRAITS_IS_REFERENCE_WRAPPER_H
11 
12 #include <__config>
13 #include <__type_traits/integral_constant.h>
14 #include <__type_traits/remove_cv.h>
15 
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #  pragma GCC system_header
18 #endif
19 
20 _LIBCPP_BEGIN_NAMESPACE_STD
21 
22 template <class _Tp>
23 class _LIBCPP_TEMPLATE_VIS reference_wrapper;
24 
25 template <class _Tp>
26 struct __is_reference_wrapper_impl : public false_type {};
27 template <class _Tp>
28 struct __is_reference_wrapper_impl<reference_wrapper<_Tp> > : public true_type {};
29 template <class _Tp>
30 struct __is_reference_wrapper : public __is_reference_wrapper_impl<__remove_cv_t<_Tp> > {};
31 
32 _LIBCPP_END_NAMESPACE_STD
33 
34 #endif // _LIBCPP___TYPE_TRAITS_ENABLE_IF_H
35