1e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===// 2e78f53d1SNikolas Klauser // 3e78f53d1SNikolas Klauser // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4e78f53d1SNikolas Klauser // See https://llvm.org/LICENSE.txt for license information. 5e78f53d1SNikolas Klauser // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6e78f53d1SNikolas Klauser // 7e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===// 8e78f53d1SNikolas Klauser 9*ce777190SNikolas Klauser #ifndef _LIBCPP___CXX03___ALGORITHM_COPY_N_H 10*ce777190SNikolas Klauser #define _LIBCPP___CXX03___ALGORITHM_COPY_N_H 11e78f53d1SNikolas Klauser 1273fbae83SNikolas Klauser #include <__cxx03/__algorithm/copy.h> 1373fbae83SNikolas Klauser #include <__cxx03/__config> 1473fbae83SNikolas Klauser #include <__cxx03/__iterator/iterator_traits.h> 1573fbae83SNikolas Klauser #include <__cxx03/__type_traits/enable_if.h> 1673fbae83SNikolas Klauser #include <__cxx03/__utility/convert_to_integral.h> 17e78f53d1SNikolas Klauser 18e78f53d1SNikolas Klauser #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19e78f53d1SNikolas Klauser # pragma GCC system_header 20e78f53d1SNikolas Klauser #endif 21e78f53d1SNikolas Klauser 22e78f53d1SNikolas Klauser _LIBCPP_BEGIN_NAMESPACE_STD 23e78f53d1SNikolas Klauser 24e78f53d1SNikolas Klauser template <class _InputIterator, 25e78f53d1SNikolas Klauser class _Size, 26e78f53d1SNikolas Klauser class _OutputIterator, 27e78f53d1SNikolas Klauser __enable_if_t<__has_input_iterator_category<_InputIterator>::value && 28e78f53d1SNikolas Klauser !__has_random_access_iterator_category<_InputIterator>::value, 29e78f53d1SNikolas Klauser int> = 0> 30e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator 31e78f53d1SNikolas Klauser copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result) { 32e78f53d1SNikolas Klauser typedef decltype(std::__convert_to_integral(__orig_n)) _IntegralSize; 33e78f53d1SNikolas Klauser _IntegralSize __n = __orig_n; 34e78f53d1SNikolas Klauser if (__n > 0) { 35e78f53d1SNikolas Klauser *__result = *__first; 36e78f53d1SNikolas Klauser ++__result; 37e78f53d1SNikolas Klauser for (--__n; __n > 0; --__n) { 38e78f53d1SNikolas Klauser ++__first; 39e78f53d1SNikolas Klauser *__result = *__first; 40e78f53d1SNikolas Klauser ++__result; 41e78f53d1SNikolas Klauser } 42e78f53d1SNikolas Klauser } 43e78f53d1SNikolas Klauser return __result; 44e78f53d1SNikolas Klauser } 45e78f53d1SNikolas Klauser 46e78f53d1SNikolas Klauser template <class _InputIterator, 47e78f53d1SNikolas Klauser class _Size, 48e78f53d1SNikolas Klauser class _OutputIterator, 49e78f53d1SNikolas Klauser __enable_if_t<__has_random_access_iterator_category<_InputIterator>::value, int> = 0> 50e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator 51e78f53d1SNikolas Klauser copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result) { 52e78f53d1SNikolas Klauser typedef typename iterator_traits<_InputIterator>::difference_type difference_type; 53e78f53d1SNikolas Klauser typedef decltype(std::__convert_to_integral(__orig_n)) _IntegralSize; 54e78f53d1SNikolas Klauser _IntegralSize __n = __orig_n; 55e78f53d1SNikolas Klauser return std::copy(__first, __first + difference_type(__n), __result); 56e78f53d1SNikolas Klauser } 57e78f53d1SNikolas Klauser 58e78f53d1SNikolas Klauser _LIBCPP_END_NAMESPACE_STD 59e78f53d1SNikolas Klauser 60*ce777190SNikolas Klauser #endif // _LIBCPP___CXX03___ALGORITHM_COPY_N_H 61