libcxx/include/__utility/cmp.h

   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___UTILITY_CMP_H
  10 #define _LIBCPP___UTILITY_CMP_H
  11
  12 #include <__config>
  13 #include <__type_traits/disjunction.h>
  14 #include <__type_traits/is_integral.h>
  15 #include <__type_traits/is_same.h>
  16 #include <__type_traits/is_signed.h>
  17 #include <__type_traits/make_unsigned.h>
  18 #include <__utility/forward.h>
  19 #include <__utility/move.h>
  20 #include <limits>
  21
  22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  23 #  pragma GCC system_header
  24 #endif
  25
  26 _LIBCPP_PUSH_MACROS
  27 #include <__undef_macros>
  28
  29 _LIBCPP_BEGIN_NAMESPACE_STD
  30
  31 #if _LIBCPP_STD_VER >= 20
  32 template<class _Tp, class... _Up>
  33 struct _IsSameAsAny : _Or<_IsSame<_Tp, _Up>...> {};
  34
  35 template<class _Tp>
  36 concept __is_safe_integral_cmp = is_integral_v<_Tp> &&
  37                       !_IsSameAsAny<_Tp, bool, char, char16_t, char32_t
  38 #ifndef _LIBCPP_HAS_NO_CHAR8_T
  39                                     , char8_t
  40 #endif
  41 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
  42                                     , wchar_t
  43 #endif
  44                                     >::value;
  45
  46 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  47 _LIBCPP_INLINE_VISIBILITY constexpr
  48 bool cmp_equal(_Tp __t, _Up __u) noexcept
  49 {
  50   if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
  51     return __t == __u;
  52   else if constexpr (is_signed_v<_Tp>)
  53     return __t < 0 ? false : make_unsigned_t<_Tp>(__t) == __u;
  54   else
  55     return __u < 0 ? false : __t == make_unsigned_t<_Up>(__u);
  56 }
  57
  58 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  59 _LIBCPP_INLINE_VISIBILITY constexpr
  60 bool cmp_not_equal(_Tp __t, _Up __u) noexcept
  61 {
  62   return !_VSTD::cmp_equal(__t, __u);
  63 }
  64
  65 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  66 _LIBCPP_INLINE_VISIBILITY constexpr
  67 bool cmp_less(_Tp __t, _Up __u) noexcept
  68 {
  69   if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
  70     return __t < __u;
  71   else if constexpr (is_signed_v<_Tp>)
  72     return __t < 0 ? true : make_unsigned_t<_Tp>(__t) < __u;
  73   else
  74     return __u < 0 ? false : __t < make_unsigned_t<_Up>(__u);
  75 }
  76
  77 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  78 _LIBCPP_INLINE_VISIBILITY constexpr
  79 bool cmp_greater(_Tp __t, _Up __u) noexcept
  80 {
  81   return _VSTD::cmp_less(__u, __t);
  82 }
  83
  84 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  85 _LIBCPP_INLINE_VISIBILITY constexpr
  86 bool cmp_less_equal(_Tp __t, _Up __u) noexcept
  87 {
  88   return !_VSTD::cmp_greater(__t, __u);
  89 }
  90
  91 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  92 _LIBCPP_INLINE_VISIBILITY constexpr
  93 bool cmp_greater_equal(_Tp __t, _Up __u) noexcept
  94 {
  95   return !_VSTD::cmp_less(__t, __u);
  96 }
  97
  98 template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
  99 _LIBCPP_INLINE_VISIBILITY constexpr
 100 bool in_range(_Up __u) noexcept
 101 {
 102   return _VSTD::cmp_less_equal(__u, numeric_limits<_Tp>::max()) &&
 103          _VSTD::cmp_greater_equal(__u, numeric_limits<_Tp>::min());
 104 }
 105 #endif // _LIBCPP_STD_VER >= 20
 106
 107 _LIBCPP_END_NAMESPACE_STD
 108
 109 _LIBCPP_POP_MACROS
 110
 111 #endif // _LIBCPP___UTILITY_CMP_H