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 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_BEGIN_NAMESPACE_STD
20 
21 #if __has_builtin(__is_signed)
22 
23 template<class _Tp>
24 struct _LIBCPP_TEMPLATE_VIS is_signed : _BoolConstant<__is_signed(_Tp)> { };
25 
26 #if _LIBCPP_STD_VER > 14
27 template <class _Tp>
28 inline constexpr bool is_signed_v = __is_signed(_Tp);
29 #endif
30 
31 #else // __has_builtin(__is_signed)
32 
33 template <class _Tp, bool = is_integral<_Tp>::value>
34 struct __libcpp_is_signed_impl : public _BoolConstant<(_Tp(-1) < _Tp(0))> {};
35 
36 template <class _Tp>
37 struct __libcpp_is_signed_impl<_Tp, false> : public true_type {};  // floating point
38 
39 template <class _Tp, bool = is_arithmetic<_Tp>::value>
40 struct __libcpp_is_signed : public __libcpp_is_signed_impl<_Tp> {};
41 
42 template <class _Tp> struct __libcpp_is_signed<_Tp, false> : public false_type {};
43 
44 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_signed : public __libcpp_is_signed<_Tp> {};
45 
46 #if _LIBCPP_STD_VER > 14
47 template <class _Tp>
48 inline constexpr bool is_signed_v = is_signed<_Tp>::value;
49 #endif
50 
51 #endif // __has_builtin(__is_signed)
52 
53 _LIBCPP_END_NAMESPACE_STD
54 
55 #endif // _LIBCPP___TYPE_TRAITS_IS_SIGNED_H
56