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___CXX03___ALGORITHM_COPY_N_H
10 #define _LIBCPP___CXX03___ALGORITHM_COPY_N_H
11
12 #include <__cxx03/__algorithm/copy.h>
13 #include <__cxx03/__config>
14 #include <__cxx03/__iterator/iterator_traits.h>
15 #include <__cxx03/__type_traits/enable_if.h>
16 #include <__cxx03/__utility/convert_to_integral.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 _InputIterator,
25 class _Size,
26 class _OutputIterator,
27 __enable_if_t<__has_input_iterator_category<_InputIterator>::value &&
28 !__has_random_access_iterator_category<_InputIterator>::value,
29 int> = 0>
copy_n(_InputIterator __first,_Size __orig_n,_OutputIterator __result)30 inline _LIBCPP_HIDE_FROM_ABI _OutputIterator copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result) {
31 typedef decltype(std::__convert_to_integral(__orig_n)) _IntegralSize;
32 _IntegralSize __n = __orig_n;
33 if (__n > 0) {
34 *__result = *__first;
35 ++__result;
36 for (--__n; __n > 0; --__n) {
37 ++__first;
38 *__result = *__first;
39 ++__result;
40 }
41 }
42 return __result;
43 }
44
45 template <class _InputIterator,
46 class _Size,
47 class _OutputIterator,
48 __enable_if_t<__has_random_access_iterator_category<_InputIterator>::value, int> = 0>
copy_n(_InputIterator __first,_Size __orig_n,_OutputIterator __result)49 inline _LIBCPP_HIDE_FROM_ABI _OutputIterator copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result) {
50 typedef typename iterator_traits<_InputIterator>::difference_type difference_type;
51 typedef decltype(std::__convert_to_integral(__orig_n)) _IntegralSize;
52 _IntegralSize __n = __orig_n;
53 return std::copy(__first, __first + difference_type(__n), __result);
54 }
55
56 _LIBCPP_END_NAMESPACE_STD
57
58 #endif // _LIBCPP___CXX03___ALGORITHM_COPY_N_H
59