__cxx03/__algorithm/merge.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CXX03___ALGORITHM_MERGE_H
0010 #define _LIBCPP___CXX03___ALGORITHM_MERGE_H
0011
0012 #include <__cxx03/__algorithm/comp.h>
0013 #include <__cxx03/__algorithm/comp_ref_type.h>
0014 #include <__cxx03/__algorithm/copy.h>
0015 #include <__cxx03/__config>
0016 #include <__cxx03/__iterator/iterator_traits.h>
0017
0018 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0019 #  pragma GCC system_header
0020 #endif
0021
0022 _LIBCPP_BEGIN_NAMESPACE_STD
0023
0024 template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
0025 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator __merge(
0026     _InputIterator1 __first1,
0027     _InputIterator1 __last1,
0028     _InputIterator2 __first2,
0029     _InputIterator2 __last2,
0030     _OutputIterator __result,
0031     _Compare __comp) {
0032   for (; __first1 != __last1; ++__result) {
0033     if (__first2 == __last2)
0034       return std::copy(__first1, __last1, __result);
0035     if (__comp(*__first2, *__first1)) {
0036       *__result = *__first2;
0037       ++__first2;
0038     } else {
0039       *__result = *__first1;
0040       ++__first1;
0041     }
0042   }
0043   return std::copy(__first2, __last2, __result);
0044 }
0045
0046 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
0047 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
0048 merge(_InputIterator1 __first1,
0049       _InputIterator1 __last1,
0050       _InputIterator2 __first2,
0051       _InputIterator2 __last2,
0052       _OutputIterator __result,
0053       _Compare __comp) {
0054   return std::__merge<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp);
0055 }
0056
0057 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
0058 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
0059 merge(_InputIterator1 __first1,
0060       _InputIterator1 __last1,
0061       _InputIterator2 __first2,
0062       _InputIterator2 __last2,
0063       _OutputIterator __result) {
0064   return std::merge(__first1, __last1, __first2, __last2, __result, __less<>());
0065 }
0066
0067 _LIBCPP_END_NAMESPACE_STD
0068
0069 #endif // _LIBCPP___CXX03___ALGORITHM_MERGE_H