Christopher Di Bella 5aaefa510e [libcxx][modules] protects users from relying on detail headers
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.

Differential Revision: https://reviews.llvm.org/D106124
2022-02-26 09:00:25 +00:00

79 lines
2.3 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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/unwrap_iter.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#include <cstring>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
# pragma clang include_instead(<algorithm>)
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
// copy
template <class _InputIterator, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
_OutputIterator
__copy_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
{
for (; __first != __last; ++__first, (void) ++__result)
*__result = *__first;
return __result;
}
template <class _InputIterator, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator
__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
{
return _VSTD::__copy_constexpr(__first, __last, __result);
}
template <class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
is_same<typename remove_const<_Tp>::type, _Up>::value &&
is_trivially_copy_assignable<_Up>::value,
_Up*
>::type
__copy(_Tp* __first, _Tp* __last, _Up* __result)
{
const size_t __n = static_cast<size_t>(__last - __first);
if (__n > 0)
_VSTD::memmove(__result, __first, __n * sizeof(_Up));
return __result + __n;
}
template <class _InputIterator, class _OutputIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
_OutputIterator
copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
{
if (__libcpp_is_constant_evaluated()) {
return _VSTD::__copy_constexpr(__first, __last, __result);
} else {
return _VSTD::__rewrap_iter(__result,
_VSTD::__copy(_VSTD::__unwrap_iter(__first),
_VSTD::__unwrap_iter(__last),
_VSTD::__unwrap_iter(__result)));
}
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_COPY_H