libcxx/include/__cxx03/__algorithm/ranges_lexicographical_compare.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___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
  10 #define _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
  11
  12 #include <__cxx03/__config>
  13 #include <__cxx03/__functional/identity.h>
  14 #include <__cxx03/__functional/invoke.h>
  15 #include <__cxx03/__functional/ranges_operations.h>
  16 #include <__cxx03/__iterator/concepts.h>
  17 #include <__cxx03/__iterator/projected.h>
  18 #include <__cxx03/__ranges/access.h>
  19 #include <__cxx03/__ranges/concepts.h>
  20 #include <__cxx03/__utility/move.h>
  21
  22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  23 #  pragma GCC system_header
  24 #endif
  25
  26 _LIBCPP_PUSH_MACROS
  27 #include <__cxx03/__undef_macros>
  28
  29 #if _LIBCPP_STD_VER >= 20
  30
  31 _LIBCPP_BEGIN_NAMESPACE_STD
  32
  33 namespace ranges {
  34 namespace __lexicographical_compare {
  35 struct __fn {
  36   template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Proj1, class _Proj2, class _Comp>
  37   _LIBCPP_HIDE_FROM_ABI constexpr static bool __lexicographical_compare_impl(
  38       _Iter1 __first1,
  39       _Sent1 __last1,
  40       _Iter2 __first2,
  41       _Sent2 __last2,
  42       _Comp& __comp,
  43       _Proj1& __proj1,
  44       _Proj2& __proj2) {
  45     while (__first2 != __last2) {
  46       if (__first1 == __last1 || std::invoke(__comp, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
  47         return true;
  48       if (std::invoke(__comp, std::invoke(__proj2, *__first2), std::invoke(__proj1, *__first1)))
  49         return false;
  50       ++__first1;
  51       ++__first2;
  52     }
  53     return false;
  54   }
  55
  56   template <input_iterator _Iter1,
  57             sentinel_for<_Iter1> _Sent1,
  58             input_iterator _Iter2,
  59             sentinel_for<_Iter2> _Sent2,
  60             class _Proj1                                                                           = identity,
  61             class _Proj2                                                                           = identity,
  62             indirect_strict_weak_order<projected<_Iter1, _Proj1>, projected<_Iter2, _Proj2>> _Comp = ranges::less>
  63   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
  64       _Iter1 __first1,
  65       _Sent1 __last1,
  66       _Iter2 __first2,
  67       _Sent2 __last2,
  68       _Comp __comp   = {},
  69       _Proj1 __proj1 = {},
  70       _Proj2 __proj2 = {}) const {
  71     return __lexicographical_compare_impl(
  72         std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2), __comp, __proj1, __proj2);
  73   }
  74
  75   template <input_range _Range1,
  76             input_range _Range2,
  77             class _Proj1 = identity,
  78             class _Proj2 = identity,
  79             indirect_strict_weak_order<projected<iterator_t<_Range1>, _Proj1>, projected<iterator_t<_Range2>, _Proj2>>
  80                 _Comp = ranges::less>
  81   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
  82       _Range1&& __range1, _Range2&& __range2, _Comp __comp = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
  83     return __lexicographical_compare_impl(
  84         ranges::begin(__range1),
  85         ranges::end(__range1),
  86         ranges::begin(__range2),
  87         ranges::end(__range2),
  88         __comp,
  89         __proj1,
  90         __proj2);
  91   }
  92 };
  93 } // namespace __lexicographical_compare
  94
  95 inline namespace __cpo {
  96 inline constexpr auto lexicographical_compare = __lexicographical_compare::__fn{};
  97 } // namespace __cpo
  98 } // namespace ranges
  99
 100 _LIBCPP_END_NAMESPACE_STD
 101
 102 #endif // _LIBCPP_STD_VER >= 20
 103
 104 _LIBCPP_POP_MACROS
 105
 106 #endif // _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H