xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/unique.h (revision 2f9966ff63d65bd474478888c9088eeae3f9c669)
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_PUSH_MACROS
25 #include <__undef_macros>
26 
27 _LIBCPP_BEGIN_NAMESPACE_STD
28 
29 // unique
30 
31 template <class _AlgPolicy, class _Iter, class _Sent, class _BinaryPredicate>
32 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 std::pair<_Iter, _Iter>
33 __unique(_Iter __first, _Sent __last, _BinaryPredicate&& __pred) {
34   __first = std::__adjacent_find(__first, __last, __pred);
35   if (__first != __last) {
36     // ...  a  a  ?  ...
37     //      f     i
38     _Iter __i = __first;
39     for (++__i; ++__i != __last;)
40       if (!__pred(*__first, *__i))
41         *++__first = _IterOps<_AlgPolicy>::__iter_move(__i);
42     ++__first;
43     return std::pair<_Iter, _Iter>(std::move(__first), std::move(__i));
44   }
45   return std::pair<_Iter, _Iter>(__first, __first);
46 }
47 
48 template <class _ForwardIterator, class _BinaryPredicate>
49 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
50 unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
51   return std::__unique<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __pred).first;
52 }
53 
54 template <class _ForwardIterator>
55 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
56 unique(_ForwardIterator __first, _ForwardIterator __last) {
57   return std::unique(__first, __last, __equal_to());
58 }
59 
60 _LIBCPP_END_NAMESPACE_STD
61 
62 _LIBCPP_POP_MACROS
63 
64 #endif // _LIBCPP___ALGORITHM_UNIQUE_H
65