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_UNIQUE_H
10#define _LIBCPP___ALGORITHM_UNIQUE_H
11
12#include <__algorithm/adjacent_find.h>
13#include <__algorithm/comp.h>
14#include <__algorithm/iterator_operations.h>
15#include <__config>
16#include <__iterator/iterator_traits.h>
17#include <__utility/move.h>
18#include <__utility/pair.h>
19
20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21#  pragma GCC system_header
22#endif
23
24_LIBCPP_BEGIN_NAMESPACE_STD
25
26// unique
27
28template <class _AlgPolicy, class _Iter, class _Sent, class _BinaryPredicate>
29_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 std::pair<_Iter, _Iter>
30__unique(_Iter __first, _Sent __last, _BinaryPredicate&& __pred) {
31  __first = std::__adjacent_find(__first, __last, __pred);
32  if (__first != __last) {
33    // ...  a  a  ?  ...
34    //      f     i
35    _Iter __i = __first;
36    for (++__i; ++__i != __last;)
37      if (!__pred(*__first, *__i))
38        *++__first = _IterOps<_AlgPolicy>::__iter_move(__i);
39    ++__first;
40    return std::pair<_Iter, _Iter>(std::move(__first), std::move(__i));
41  }
42  return std::pair<_Iter, _Iter>(__first, __first);
43}
44
45template <class _ForwardIterator, class _BinaryPredicate>
46_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
47unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
48  return std::__unique<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __pred).first;
49}
50
51template <class _ForwardIterator>
52_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
53unique(_ForwardIterator __first, _ForwardIterator __last) {
54  return std::unique(__first, __last, __equal_to());
55}
56
57_LIBCPP_END_NAMESPACE_STD
58
59#endif // _LIBCPP___ALGORITHM_UNIQUE_H
60