libcxx/include/__cxx03/__algorithm/merge.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_MERGE_H
  10 #define _LIBCPP___ALGORITHM_MERGE_H
  11
  12 #include <__cxx03/__algorithm/comp.h>
  13 #include <__cxx03/__algorithm/comp_ref_type.h>
  14 #include <__cxx03/__algorithm/copy.h>
  15 #include <__cxx03/__config>
  16 #include <__cxx03/__iterator/iterator_traits.h>
  17
  18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19 #  pragma GCC system_header
  20 #endif
  21
  22 _LIBCPP_BEGIN_NAMESPACE_STD
  23
  24 template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
  25 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator __merge(
  26     _InputIterator1 __first1,
  27     _InputIterator1 __last1,
  28     _InputIterator2 __first2,
  29     _InputIterator2 __last2,
  30     _OutputIterator __result,
  31     _Compare __comp) {
  32   for (; __first1 != __last1; ++__result) {
  33     if (__first2 == __last2)
  34       return std::copy(__first1, __last1, __result);
  35     if (__comp(*__first2, *__first1)) {
  36       *__result = *__first2;
  37       ++__first2;
  38     } else {
  39       *__result = *__first1;
  40       ++__first1;
  41     }
  42   }
  43   return std::copy(__first2, __last2, __result);
  44 }
  45
  46 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  47 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
  48 merge(_InputIterator1 __first1,
  49       _InputIterator1 __last1,
  50       _InputIterator2 __first2,
  51       _InputIterator2 __last2,
  52       _OutputIterator __result,
  53       _Compare __comp) {
  54   return std::__merge<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp);
  55 }
  56
  57 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  58 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
  59 merge(_InputIterator1 __first1,
  60       _InputIterator1 __last1,
  61       _InputIterator2 __first2,
  62       _InputIterator2 __last2,
  63       _OutputIterator __result) {
  64   return std::merge(__first1, __last1, __first2, __last2, __result, __less<>());
  65 }
  66
  67 _LIBCPP_END_NAMESPACE_STD
  68
  69 #endif // _LIBCPP___ALGORITHM_MERGE_H