libcxx/include/__cxx03/__algorithm/unique.h

   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 <__cxx03/__algorithm/adjacent_find.h>
  13 #include <__cxx03/__algorithm/comp.h>
  14 #include <__cxx03/__algorithm/iterator_operations.h>
  15 #include <__cxx03/__config>
  16 #include <__cxx03/__iterator/iterator_traits.h>
  17 #include <__cxx03/__utility/move.h>
  18 #include <__cxx03/__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 <__cxx03/__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 _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 _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 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