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//===----------------------------------------------------------------------===//
//
// 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_N_H
#define _LIBCPP___ALGORITHM_COPY_N_H
#include <__algorithm/copy.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#include <__utility/convert_to_integral.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template<class _InputIterator, class _Size, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
typename enable_if
<
__is_cpp17_input_iterator<_InputIterator>::value &&
!__is_cpp17_random_access_iterator<_InputIterator>::value,
_OutputIterator
>::type
copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
{
typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
_IntegralSize __n = __orig_n;
if (__n > 0)
{
*__result = *__first;
++__result;
for (--__n; __n > 0; --__n)
{
++__first;
*__result = *__first;
++__result;
}
}
return __result;
}
template<class _InputIterator, class _Size, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
typename enable_if
<
__is_cpp17_random_access_iterator<_InputIterator>::value,
_OutputIterator
>::type
copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
{
typedef typename iterator_traits<_InputIterator>::difference_type difference_type;
typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
_IntegralSize __n = __orig_n;
return _VSTD::copy(__first, __first + difference_type(__n), __result);
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_COPY_N_H
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