xref: /llvm-project/libcxx/include/__algorithm/adjacent_find.h (revision b905bcc5090cde734e8b7bbceae13bd5a606cc14)

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_ADJACENT_FIND_H
#define _LIBCPP___ALGORITHM_ADJACENT_FIND_H

#include <__algorithm/comp.h>
#include <__config>
#include <__functional/identity.h>
#include <__type_traits/invoke.h>
#include <__utility/move.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Iter, class _Sent, class _Pred, class _Proj>
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter
__adjacent_find(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
  if (__first == __last)
    return __first;

  _Iter __i = __first;
  while (++__i != __last) {
    if (std::__invoke(__pred, std::__invoke(__proj, *__first), std::__invoke(__proj, *__i)))
      return __first;
    __first = __i;
  }
  return __i;
}

template <class _ForwardIterator, class _BinaryPredicate>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
  __identity __proj;
  return std::__adjacent_find(std::move(__first), std::move(__last), __pred, __proj);
}

template <class _ForwardIterator>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
adjacent_find(_ForwardIterator __first, _ForwardIterator __last) {
  return std::adjacent_find(std::move(__first), std::move(__last), __equal_to());
}

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // _LIBCPP___ALGORITHM_ADJACENT_FIND_H