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