368faacac7
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9, which were related to the original commit). As landed, 5aaefa51 had unintended consequences on some downstream bots and didn't have proper coverage upstream due to a few subtle things. Implementing this is something we should do in libc++, however we'll first need to address a few issues listed in https://reviews.llvm.org/D106124#3349710. Differential Revision: https://reviews.llvm.org/D120683
87 lines
2.4 KiB
C++
87 lines
2.4 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___ITERATOR_NEXT_H
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#define _LIBCPP___ITERATOR_NEXT_H
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#include <__assert>
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#include <__config>
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#include <__iterator/advance.h>
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#include <__iterator/concepts.h>
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#include <__iterator/incrementable_traits.h>
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#include <__iterator/iterator_traits.h>
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#include <type_traits>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_BEGIN_NAMESPACE_STD
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template <class _InputIter>
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inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
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typename enable_if<__is_cpp17_input_iterator<_InputIter>::value, _InputIter>::type
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next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) {
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_LIBCPP_ASSERT(__n >= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
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"Attempt to next(it, n) with negative n on a non-bidirectional iterator");
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_VSTD::advance(__x, __n);
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return __x;
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}
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#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
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// [range.iter.op.next]
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namespace ranges {
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namespace __next {
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struct __fn {
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template <input_or_output_iterator _Ip>
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_LIBCPP_HIDE_FROM_ABI
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constexpr _Ip operator()(_Ip __x) const {
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++__x;
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return __x;
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}
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template <input_or_output_iterator _Ip>
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_LIBCPP_HIDE_FROM_ABI
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constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n) const {
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ranges::advance(__x, __n);
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return __x;
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}
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template <input_or_output_iterator _Ip, sentinel_for<_Ip> _Sp>
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_LIBCPP_HIDE_FROM_ABI
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constexpr _Ip operator()(_Ip __x, _Sp __bound) const {
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ranges::advance(__x, __bound);
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return __x;
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}
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template <input_or_output_iterator _Ip, sentinel_for<_Ip> _Sp>
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_LIBCPP_HIDE_FROM_ABI
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constexpr _Ip operator()(_Ip __x, iter_difference_t<_Ip> __n, _Sp __bound) const {
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ranges::advance(__x, __n, __bound);
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return __x;
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}
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};
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} // namespace __next
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inline namespace __cpo {
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inline constexpr auto next = __next::__fn{};
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} // namespace __cpo
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} // namespace ranges
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#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___ITERATOR_NEXT_H
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