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_FUNCTIONAL_H
10 #define _LIBCPP___TYPE_TRAITS_IS_FUNCTIONAL_H
11 
12 #include <__config>
13 #include <__type_traits/integral_constant.h>
14 #include <__type_traits/is_const.h>
15 #include <__type_traits/is_reference.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 #if __has_builtin(__is_function)
24 
25 template <class _Tp>
26 struct _LIBCPP_TEMPLATE_VIS is_function : integral_constant<bool, __is_function(_Tp)> {};
27 
28 #else
29 
30 template <class _Tp>
31 struct _LIBCPP_TEMPLATE_VIS is_function
32     : public integral_constant<bool, !(is_reference<_Tp>::value || is_const<const _Tp>::value)> {};
33 
34 #endif // __has_builtin(__is_function)
35 
36 #if _LIBCPP_STD_VER >= 17
37 template <class _Tp>
38 inline constexpr bool is_function_v = is_function<_Tp>::value;
39 #endif
40 
41 _LIBCPP_END_NAMESPACE_STD
42 
43 #endif // _LIBCPP___TYPE_TRAITS_IS_FUNCTIONAL_H
44