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 <__fwd/functional.h> 14 #include <__type_traits/integral_constant.h> 15 #include <__type_traits/remove_cv.h> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 template <class _Tp> 24 struct __is_reference_wrapper_impl : public false_type {}; 25 template <class _Tp> 26 struct __is_reference_wrapper_impl<reference_wrapper<_Tp> > : public true_type {}; 27 template <class _Tp> 28 struct __is_reference_wrapper : public __is_reference_wrapper_impl<__remove_cv_t<_Tp> > {}; 29 30 _LIBCPP_END_NAMESPACE_STD 31 32 #endif // _LIBCPP___TYPE_TRAITS_ENABLE_IF_H 33