copy.h revision 1.1.1.1 
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___ALGORITHM_COPY_H
10#define _LIBCPP___ALGORITHM_COPY_H
11
12#include <__config>
13#include <__algorithm/unwrap_iter.h>
14#include <__iterator/iterator_traits.h>
15#include <cstring>
16#include <type_traits>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#pragma GCC system_header
20#endif
21
22_LIBCPP_PUSH_MACROS
23#include <__undef_macros>
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27// copy
28
29template <class _InputIterator, class _OutputIterator>
30inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
31_OutputIterator
32__copy_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
33{
34    for (; __first != __last; ++__first, (void) ++__result)
35        *__result = *__first;
36    return __result;
37}
38
39template <class _InputIterator, class _OutputIterator>
40inline _LIBCPP_INLINE_VISIBILITY
41_OutputIterator
42__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
43{
44    return _VSTD::__copy_constexpr(__first, __last, __result);
45}
46
47template <class _Tp, class _Up>
48inline _LIBCPP_INLINE_VISIBILITY
49typename enable_if
50<
51    is_same<typename remove_const<_Tp>::type, _Up>::value &&
52    is_trivially_copy_assignable<_Up>::value,
53    _Up*
54>::type
55__copy(_Tp* __first, _Tp* __last, _Up* __result)
56{
57    const size_t __n = static_cast<size_t>(__last - __first);
58    if (__n > 0)
59        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
60    return __result + __n;
61}
62
63template <class _InputIterator, class _OutputIterator>
64inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
65_OutputIterator
66copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
67{
68    if (__libcpp_is_constant_evaluated()) {
69        return _VSTD::__copy_constexpr(__first, __last, __result);
70    } else {
71        return _VSTD::__rewrap_iter(__result,
72            _VSTD::__copy(_VSTD::__unwrap_iter(__first),
73                          _VSTD::__unwrap_iter(__last),
74                          _VSTD::__unwrap_iter(__result)));
75    }
76}
77
78_LIBCPP_END_NAMESPACE_STD
79
80_LIBCPP_POP_MACROS
81
82#endif // _LIBCPP___ALGORITHM_COPY_H
83