libcxx/include/__cxx03/__algorithm/equal.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___ALGORITHM_EQUAL_H
  11 #define _LIBCPP___ALGORITHM_EQUAL_H
  12
  13 #include <__cxx03/__algorithm/comp.h>
  14 #include <__cxx03/__algorithm/unwrap_iter.h>
  15 #include <__cxx03/__config>
  16 #include <__cxx03/__functional/identity.h>
  17 #include <__cxx03/__functional/invoke.h>
  18 #include <__cxx03/__iterator/distance.h>
  19 #include <__cxx03/__iterator/iterator_traits.h>
  20 #include <__cxx03/__string/constexpr_c_functions.h>
  21 #include <__cxx03/__type_traits/desugars_to.h>
  22 #include <__cxx03/__type_traits/enable_if.h>
  23 #include <__cxx03/__type_traits/is_constant_evaluated.h>
  24 #include <__cxx03/__type_traits/is_equality_comparable.h>
  25 #include <__cxx03/__type_traits/is_volatile.h>
  26 #include <__cxx03/__utility/move.h>
  27
  28 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  29 #  pragma GCC system_header
  30 #endif
  31
  32 _LIBCPP_PUSH_MACROS
  33 #include <__cxx03/__undef_macros>
  34
  35 _LIBCPP_BEGIN_NAMESPACE_STD
  36
  37 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
  38 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_iter_impl(
  39     _InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate& __pred) {
  40   for (; __first1 != __last1; ++__first1, (void)++__first2)
  41     if (!__pred(*__first1, *__first2))
  42       return false;
  43   return true;
  44 }
  45
  46 template <class _Tp,
  47           class _Up,
  48           class _BinaryPredicate,
  49           __enable_if_t<__desugars_to_v<__equal_tag, _BinaryPredicate, _Tp, _Up> && !is_volatile<_Tp>::value &&
  50                             !is_volatile<_Up>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
  51                         int> = 0>
  52 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  53 __equal_iter_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _BinaryPredicate&) {
  54   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
  55 }
  56
  57 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
  58 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  59 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
  60   return std::__equal_iter_impl(
  61       std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred);
  62 }
  63
  64 template <class _InputIterator1, class _InputIterator2>
  65 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  66 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
  67   return std::equal(__first1, __last1, __first2, __equal_to());
  68 }
  69
  70 #if _LIBCPP_STD_VER >= 14
  71
  72 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
  73 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
  74     _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __comp, _Proj1& __proj1, _Proj2& __proj2) {
  75   while (__first1 != __last1 && __first2 != __last2) {
  76     if (!std::__invoke(__comp, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
  77       return false;
  78     ++__first1;
  79     ++__first2;
  80   }
  81   return __first1 == __last1 && __first2 == __last2;
  82 }
  83
  84 template <class _Tp,
  85           class _Up,
  86           class _Pred,
  87           class _Proj1,
  88           class _Proj2,
  89           __enable_if_t<__desugars_to_v<__equal_tag, _Pred, _Tp, _Up> && __is_identity<_Proj1>::value &&
  90                             __is_identity<_Proj2>::value && !is_volatile<_Tp>::value && !is_volatile<_Up>::value &&
  91                             __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
  92                         int> = 0>
  93 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  94 __equal_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&, _Proj2&) {
  95   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
  96 }
  97
  98 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
  99 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 100 equal(_InputIterator1 __first1,
 101       _InputIterator1 __last1,
 102       _InputIterator2 __first2,
 103       _InputIterator2 __last2,
 104       _BinaryPredicate __pred) {
 105   if constexpr (__has_random_access_iterator_category<_InputIterator1>::value &&
 106                 __has_random_access_iterator_category<_InputIterator2>::value) {
 107     if (std::distance(__first1, __last1) != std::distance(__first2, __last2))
 108       return false;
 109   }
 110   __identity __proj;
 111   return std::__equal_impl(
 112       std::__unwrap_iter(__first1),
 113       std::__unwrap_iter(__last1),
 114       std::__unwrap_iter(__first2),
 115       std::__unwrap_iter(__last2),
 116       __pred,
 117       __proj,
 118       __proj);
 119 }
 120
 121 template <class _InputIterator1, class _InputIterator2>
 122 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 123 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
 124   return std::equal(__first1, __last1, __first2, __last2, __equal_to());
 125 }
 126
 127 #endif // _LIBCPP_STD_VER >= 14
 128
 129 _LIBCPP_END_NAMESPACE_STD
 130
 131 _LIBCPP_POP_MACROS
 132
 133 #endif // _LIBCPP___ALGORITHM_EQUAL_H