libcxx/include/__algorithm/set_difference.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_SET_DIFFERENCE_H
  10 #define _LIBCPP___ALGORITHM_SET_DIFFERENCE_H
  11
  12 #include <__algorithm/comp.h>
  13 #include <__algorithm/comp_ref_type.h>
  14 #include <__algorithm/copy.h>
  15 #include <__config>
  16 #include <__functional/identity.h>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__type_traits/remove_cvref.h>
  19 #include <__utility/move.h>
  20 #include <__utility/pair.h>
  21
  22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  23 #  pragma GCC system_header
  24 #endif
  25
  26 _LIBCPP_PUSH_MACROS
  27 #include <__undef_macros>
  28
  29 _LIBCPP_BEGIN_NAMESPACE_STD
  30
  31 template <class _Comp, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
  32 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<__remove_cvref_t<_InIter1>, __remove_cvref_t<_OutIter> >
  33 __set_difference(
  34     _InIter1&& __first1, _Sent1&& __last1, _InIter2&& __first2, _Sent2&& __last2, _OutIter&& __result, _Comp&& __comp) {
  35   while (__first1 != __last1 && __first2 != __last2) {
  36     if (__comp(*__first1, *__first2)) {
  37       *__result = *__first1;
  38       ++__first1;
  39       ++__result;
  40     } else if (__comp(*__first2, *__first1)) {
  41       ++__first2;
  42     } else {
  43       ++__first1;
  44       ++__first2;
  45     }
  46   }
  47   return std::__copy(std::move(__first1), std::move(__last1), std::move(__result));
  48 }
  49
  50 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  51 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_difference(
  52     _InputIterator1 __first1,
  53     _InputIterator1 __last1,
  54     _InputIterator2 __first2,
  55     _InputIterator2 __last2,
  56     _OutputIterator __result,
  57     _Compare __comp) {
  58   return std::__set_difference<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp)
  59       .second;
  60 }
  61
  62 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  63 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_difference(
  64     _InputIterator1 __first1,
  65     _InputIterator1 __last1,
  66     _InputIterator2 __first2,
  67     _InputIterator2 __last2,
  68     _OutputIterator __result) {
  69   return std::__set_difference(__first1, __last1, __first2, __last2, __result, __less<>()).second;
  70 }
  71
  72 _LIBCPP_END_NAMESPACE_STD
  73
  74 _LIBCPP_POP_MACROS
  75
  76 #endif // _LIBCPP___ALGORITHM_SET_DIFFERENCE_H