libcxx/include/__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 <__algorithm/comp.h>
  14 #include <__algorithm/unwrap_iter.h>
  15 #include <__config>
  16 #include <__functional/identity.h>
  17 #include <__functional/invoke.h>
  18 #include <__iterator/distance.h>
  19 #include <__iterator/iterator_traits.h>
  20 #include <__string/constexpr_c_functions.h>
  21 #include <__type_traits/enable_if.h>
  22 #include <__type_traits/integral_constant.h>
  23 #include <__type_traits/is_constant_evaluated.h>
  24 #include <__type_traits/is_equality_comparable.h>
  25 #include <__type_traits/is_volatile.h>
  26 #include <__type_traits/predicate_traits.h>
  27 #include <__utility/move.h>
  28
  29 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  30 #  pragma GCC system_header
  31 #endif
  32
  33 _LIBCPP_BEGIN_NAMESPACE_STD
  34
  35 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
  36 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_iter_impl(
  37     _InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate& __pred) {
  38   for (; __first1 != __last1; ++__first1, (void)++__first2)
  39     if (!__pred(*__first1, *__first2))
  40       return false;
  41   return true;
  42 }
  43
  44 template <
  45     class _Tp,
  46     class _Up,
  47     class _BinaryPredicate,
  48     __enable_if_t<__is_trivial_equality_predicate<_BinaryPredicate, _Tp, _Up>::value && !is_volatile<_Tp>::value &&
  49                       !is_volatile<_Up>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
  50                   int> = 0>
  51 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  52 __equal_iter_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _BinaryPredicate&) {
  53   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
  54 }
  55
  56 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
  57 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  58 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
  59   return std::__equal_iter_impl(
  60       std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred);
  61 }
  62
  63 template <class _InputIterator1, class _InputIterator2>
  64 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  65 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
  66   return std::equal(__first1, __last1, __first2, __equal_to());
  67 }
  68
  69 #if _LIBCPP_STD_VER >= 14
  70 template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
  71 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
  72 __equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
  73         _BinaryPredicate __pred, input_iterator_tag, input_iterator_tag) {
  74   for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
  75     if (!__pred(*__first1, *__first2))
  76       return false;
  77   return __first1 == __last1 && __first2 == __last2;
  78 }
  79
  80 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
  81 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
  82     _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __comp, _Proj1& __proj1, _Proj2& __proj2) {
  83   while (__first1 != __last1 && __first2 != __last2) {
  84     if (!std::__invoke(__comp, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
  85       return false;
  86     ++__first1;
  87     ++__first2;
  88   }
  89   return __first1 == __last1 && __first2 == __last2;
  90 }
  91
  92 template <class _Tp,
  93           class _Up,
  94           class _Pred,
  95           class _Proj1,
  96           class _Proj2,
  97           __enable_if_t<__is_trivial_equality_predicate<_Pred, _Tp, _Up>::value && __is_identity<_Proj1>::value &&
  98                             __is_identity<_Proj2>::value && !is_volatile<_Tp>::value && !is_volatile<_Up>::value &&
  99                             __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
 100                         int> = 0>
 101 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
 102     _Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&, _Proj2&) {
 103   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
 104 }
 105
 106 template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
 107 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 108 __equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
 109         _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag,
 110         random_access_iterator_tag) {
 111   if (_VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
 112     return false;
 113   __identity __proj;
 114   return std::__equal_impl(
 115       std::__unwrap_iter(__first1),
 116       std::__unwrap_iter(__last1),
 117       std::__unwrap_iter(__first2),
 118       std::__unwrap_iter(__last2),
 119       __pred,
 120       __proj,
 121       __proj);
 122 }
 123
 124 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
 125 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 126 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
 127       _BinaryPredicate __pred) {
 128   return _VSTD::__equal<_BinaryPredicate&>(
 129       __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_InputIterator1>::iterator_category(),
 130       typename iterator_traits<_InputIterator2>::iterator_category());
 131 }
 132
 133 template <class _InputIterator1, class _InputIterator2>
 134 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 135 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
 136   return std::__equal(
 137       __first1,
 138       __last1,
 139       __first2,
 140       __last2,
 141       __equal_to(),
 142       typename iterator_traits<_InputIterator1>::iterator_category(),
 143       typename iterator_traits<_InputIterator2>::iterator_category());
 144 }
 145 #endif
 146
 147 _LIBCPP_END_NAMESPACE_STD
 148
 149 #endif // _LIBCPP___ALGORITHM_EQUAL_H