libcxx/include/__algorithm/adjacent_find.h

// -*- 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 <__config>
#include <__algorithm/comp.h>
#include <__iterator/iterator_traits.h>

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

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _ForwardIterator, class _BinaryPredicate>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
  if (__first != __last) {
    _ForwardIterator __i = __first;
    while (++__i != __last) {
      if (__pred(*__first, *__i))
        return __first;
      __first = __i;
    }
  }
  return __last;
}

template <class _ForwardIterator>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
adjacent_find(_ForwardIterator __first, _ForwardIterator __last) {
  typedef typename iterator_traits<_ForwardIterator>::value_type __v;
  return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
}

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ALGORITHM_ADJACENT_FIND_H