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 25 template <class _Tp> 26 struct _LIBCPP_TEMPLATE_VIS is_signed : _BoolConstant<__is_signed(_Tp)> {}; 27 28 # if _LIBCPP_STD_VER >= 17 29 template <class _Tp> 30 inline constexpr bool is_signed_v = __is_signed(_Tp); 31 # endif 32 33 #else // __has_builtin(__is_signed) 34 35 template <class _Tp, bool = is_integral<_Tp>::value> 36 struct __libcpp_is_signed_impl : public _BoolConstant<(_Tp(-1) < _Tp(0))> {}; 37 38 template <class _Tp> 39 struct __libcpp_is_signed_impl<_Tp, false> : public true_type {}; // floating point 40 41 template <class _Tp, bool = is_arithmetic<_Tp>::value> 42 struct __libcpp_is_signed : public __libcpp_is_signed_impl<_Tp> {}; 43 44 template <class _Tp> 45 struct __libcpp_is_signed<_Tp, false> : public false_type {}; 46 47 template <class _Tp> 48 struct _LIBCPP_TEMPLATE_VIS is_signed : public __libcpp_is_signed<_Tp> {}; 49 50 # if _LIBCPP_STD_VER >= 17 51 template <class _Tp> 52 inline constexpr bool is_signed_v = is_signed<_Tp>::value; 53 # endif 54 55 #endif // __has_builtin(__is_signed) 56 57 _LIBCPP_END_NAMESPACE_STD 58 59 #endif // _LIBCPP___TYPE_TRAITS_IS_SIGNED_H 60