e78f53d1e8
This reverts commit 68c04b0ae62d8431d72d8b47fc13008002ee4387. This disables the IWYU mapping that caused the failure, since the headers aren't reachable for now. This is the first part of the "Freezing C++03 headers" proposal explained in https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc/77319/58. This patch mechanically copies the headers as of the LLVM 19.1 release into a subdirectory of libc++ so that we can start using these headers when building in C++03 mode. We are going to be backporting important changes to that copy of the headers until the LLVM 21 release. After the LLVM 21 release, only critical bugfixes will be fixed in the C++03 copy of the headers. This patch only performs a copy of the headers -- these headers are still unused by the rest of the codebase.
77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
// -*- 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___ITERATOR_PREV_H
|
|
#define _LIBCPP___ITERATOR_PREV_H
|
|
|
|
#include <__assert>
|
|
#include <__config>
|
|
#include <__iterator/advance.h>
|
|
#include <__iterator/concepts.h>
|
|
#include <__iterator/incrementable_traits.h>
|
|
#include <__iterator/iterator_traits.h>
|
|
#include <__type_traits/enable_if.h>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
|
|
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 _InputIter
|
|
prev(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) {
|
|
// Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation.
|
|
// Note that this check duplicates the similar check in `std::advance`.
|
|
_LIBCPP_ASSERT_PEDANTIC(__n <= 0 || __has_bidirectional_iterator_category<_InputIter>::value,
|
|
"Attempt to prev(it, n) with a positive n on a non-bidirectional iterator");
|
|
std::advance(__x, -__n);
|
|
return __x;
|
|
}
|
|
|
|
#if _LIBCPP_STD_VER >= 20
|
|
|
|
// [range.iter.op.prev]
|
|
|
|
namespace ranges {
|
|
namespace __prev {
|
|
|
|
struct __fn {
|
|
template <bidirectional_iterator _Ip>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x) const {
|
|
--__x;
|
|
return __x;
|
|
}
|
|
|
|
template <bidirectional_iterator _Ip>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n) const {
|
|
ranges::advance(__x, -__n);
|
|
return __x;
|
|
}
|
|
|
|
template <bidirectional_iterator _Ip>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n, _Ip __bound_iter) const {
|
|
ranges::advance(__x, -__n, __bound_iter);
|
|
return __x;
|
|
}
|
|
};
|
|
|
|
} // namespace __prev
|
|
|
|
inline namespace __cpo {
|
|
inline constexpr auto prev = __prev::__fn{};
|
|
} // namespace __cpo
|
|
} // namespace ranges
|
|
|
|
#endif // _LIBCPP_STD_VER >= 20
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___ITERATOR_PREV_H
|