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___UTILITY_DECLVAL_H 10 #define _LIBCPP___UTILITY_DECLVAL_H 11 12 #include <__config> 13 14 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 15 #pragma GCC system_header 16 #endif 17 18 _LIBCPP_PUSH_MACROS 19 #include <__undef_macros> 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 // Suppress deprecation notice for volatile-qualified return type resulting 24 // from volatile-qualified types _Tp. 25 _LIBCPP_SUPPRESS_DEPRECATED_PUSH 26 template <class _Tp> 27 _Tp&& __declval(int); 28 template <class _Tp> 29 _Tp __declval(long); 30 _LIBCPP_SUPPRESS_DEPRECATED_POP 31 32 template <class _Tp> 33 decltype(__declval<_Tp>(0)) declval() _NOEXCEPT; 34 35 _LIBCPP_END_NAMESPACE_STD 36 37 _LIBCPP_POP_MACROS 38 39 #endif // _LIBCPP___UTILITY_DECLVAL_H 40