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.
124 lines
4.2 KiB
C++
124 lines
4.2 KiB
C++
//===----------------------------------------------------------------------===//
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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___ALGORITHM_SAMPLE_H
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#define _LIBCPP___ALGORITHM_SAMPLE_H
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#include <__algorithm/iterator_operations.h>
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#include <__algorithm/min.h>
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#include <__assert>
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#include <__config>
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#include <__iterator/distance.h>
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#include <__iterator/iterator_traits.h>
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#include <__random/uniform_int_distribution.h>
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#include <__type_traits/common_type.h>
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#include <__utility/move.h>
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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_PUSH_MACROS
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#include <__undef_macros>
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_LIBCPP_BEGIN_NAMESPACE_STD
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template <class _AlgPolicy,
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class _PopulationIterator,
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class _PopulationSentinel,
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class _SampleIterator,
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class _Distance,
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class _UniformRandomNumberGenerator>
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_LIBCPP_HIDE_FROM_ABI _SampleIterator __sample(
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_PopulationIterator __first,
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_PopulationSentinel __last,
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_SampleIterator __output_iter,
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_Distance __n,
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_UniformRandomNumberGenerator& __g,
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input_iterator_tag) {
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_Distance __k = 0;
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for (; __first != __last && __k < __n; ++__first, (void)++__k)
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__output_iter[__k] = *__first;
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_Distance __sz = __k;
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for (; __first != __last; ++__first, (void)++__k) {
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_Distance __r = uniform_int_distribution<_Distance>(0, __k)(__g);
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if (__r < __sz)
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__output_iter[__r] = *__first;
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}
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return __output_iter + std::min(__n, __k);
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}
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template <class _AlgPolicy,
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class _PopulationIterator,
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class _PopulationSentinel,
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class _SampleIterator,
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class _Distance,
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class _UniformRandomNumberGenerator>
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_LIBCPP_HIDE_FROM_ABI _SampleIterator __sample(
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_PopulationIterator __first,
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_PopulationSentinel __last,
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_SampleIterator __output_iter,
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_Distance __n,
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_UniformRandomNumberGenerator& __g,
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forward_iterator_tag) {
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_Distance __unsampled_sz = _IterOps<_AlgPolicy>::distance(__first, __last);
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for (__n = std::min(__n, __unsampled_sz); __n != 0; ++__first) {
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_Distance __r = uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
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if (__r < __n) {
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*__output_iter++ = *__first;
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--__n;
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}
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}
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return __output_iter;
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}
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template <class _AlgPolicy,
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class _PopulationIterator,
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class _PopulationSentinel,
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class _SampleIterator,
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class _Distance,
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class _UniformRandomNumberGenerator>
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_LIBCPP_HIDE_FROM_ABI _SampleIterator __sample(
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_PopulationIterator __first,
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_PopulationSentinel __last,
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_SampleIterator __output_iter,
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_Distance __n,
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_UniformRandomNumberGenerator& __g) {
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_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n >= 0, "N must be a positive number.");
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using _PopIterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_PopulationIterator>;
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using _Difference = typename _IterOps<_AlgPolicy>::template __difference_type<_PopulationIterator>;
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using _CommonType = typename common_type<_Distance, _Difference>::type;
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return std::__sample<_AlgPolicy>(
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std::move(__first), std::move(__last), std::move(__output_iter), _CommonType(__n), __g, _PopIterCategory());
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}
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#if _LIBCPP_STD_VER >= 17
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template <class _PopulationIterator, class _SampleIterator, class _Distance, class _UniformRandomNumberGenerator>
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inline _LIBCPP_HIDE_FROM_ABI _SampleIterator
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sample(_PopulationIterator __first,
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_PopulationIterator __last,
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_SampleIterator __output_iter,
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_Distance __n,
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_UniformRandomNumberGenerator&& __g) {
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static_assert(__has_forward_iterator_category<_PopulationIterator>::value ||
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__has_random_access_iterator_category<_SampleIterator>::value,
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"SampleIterator must meet the requirements of RandomAccessIterator");
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return std::__sample<_ClassicAlgPolicy>(std::move(__first), std::move(__last), std::move(__output_iter), __n, __g);
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}
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#endif // _LIBCPP_STD_VER >= 17
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_LIBCPP_END_NAMESPACE_STD
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_LIBCPP_POP_MACROS
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#endif // _LIBCPP___ALGORITHM_SAMPLE_H
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