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_SIGNED_H
10#define _LIBCPP___TYPE_TRAITS_IS_SIGNED_H
11
12#include <__config>
13#include <__type_traits/integral_constant.h>
14#include <__type_traits/is_arithmetic.h>
15#include <__type_traits/is_integral.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_signed)
24
25template<class _Tp>
26struct _LIBCPP_TEMPLATE_VIS is_signed : _BoolConstant<__is_signed(_Tp)> { };
27
28#if _LIBCPP_STD_VER > 14
29template <class _Tp>
30inline constexpr bool is_signed_v = __is_signed(_Tp);
31#endif
32
33#else // __has_builtin(__is_signed)
34
35template <class _Tp, bool = is_integral<_Tp>::value>
36struct __libcpp_is_signed_impl : public _BoolConstant<(_Tp(-1) < _Tp(0))> {};
37
38template <class _Tp>
39struct __libcpp_is_signed_impl<_Tp, false> : public true_type {};  // floating point
40
41template <class _Tp, bool = is_arithmetic<_Tp>::value>
42struct __libcpp_is_signed : public __libcpp_is_signed_impl<_Tp> {};
43
44template <class _Tp> struct __libcpp_is_signed<_Tp, false> : public false_type {};
45
46template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_signed : public __libcpp_is_signed<_Tp> {};
47
48#if _LIBCPP_STD_VER > 14
49template <class _Tp>
50inline constexpr bool is_signed_v = is_signed<_Tp>::value;
51#endif
52
53#endif // __has_builtin(__is_signed)
54
55_LIBCPP_END_NAMESPACE_STD
56
57#endif // _LIBCPP___TYPE_TRAITS_IS_SIGNED_H
58