third_party/llvm-project/libcxx/include/__algorithm/copy.h

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_COPY_H
#define _LIBCPP___ALGORITHM_COPY_H

#include <__algorithm/copy_move_common.h>
#include <__algorithm/iterator_operations.h>
#include <__config>
#include <__utility/move.h>
#include <__utility/pair.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

struct __copy_loop {
  template <class _InIter, class _Sent, class _OutIter>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
  operator()(_InIter __first, _Sent __last, _OutIter __result) const {
    while (__first != __last) {
      *__result = *__first;
      ++__first;
      ++__result;
    }

    return std::make_pair(std::move(__first), std::move(__result));
  }
};

struct __copy_trivial {
  // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer.
  template <class _In, class _Out,
            __enable_if_t<__can_lower_copy_assignment_to_memmove<_In, _Out>::value, int> = 0>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*>
  operator()(_In* __first, _In* __last, _Out* __result) const {
    return std::__copy_trivial_impl(__first, __last, __result);
  }
};

template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
pair<_InIter, _OutIter>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
__copy(_InIter __first, _Sent __last, _OutIter __result) {
  return std::__dispatch_copy_or_move<_AlgPolicy, __copy_loop, __copy_trivial>(
      std::move(__first), std::move(__last), std::move(__result));
}

template <class _InputIterator, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
_OutputIterator
copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
  return std::__copy<_ClassicAlgPolicy>(__first, __last, __result).second;
}

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ALGORITHM_COPY_H