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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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___ALGORITHM_FOR_EACH_SEGMENT_H10#define _LIBCPP___ALGORITHM_FOR_EACH_SEGMENT_H11 12#include <__config>13#include <__iterator/segmented_iterator.h>14 15#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)16# pragma GCC system_header17#endif18 19_LIBCPP_BEGIN_NAMESPACE_STD20 21// __for_each_segment is a utility function for optimizing iterating over segmented iterators linearly.22// __first and __last are expected to be a segmented range. __func is expected to take a range of local iterators.23// Anything that is returned from __func is ignored.24 25template <class _SegmentedIterator, class _Functor>26_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void27__for_each_segment(_SegmentedIterator __first, _SegmentedIterator __last, _Functor __func) {28 using _Traits = __segmented_iterator_traits<_SegmentedIterator>;29 30 auto __sfirst = _Traits::__segment(__first);31 auto __slast = _Traits::__segment(__last);32 33 // We are in a single segment, so we might not be at the beginning or end34 if (__sfirst == __slast) {35 __func(_Traits::__local(__first), _Traits::__local(__last));36 return;37 }38 39 // We have more than one segment. Iterate over the first segment, since we might not start at the beginning40 __func(_Traits::__local(__first), _Traits::__end(__sfirst));41 ++__sfirst;42 // iterate over the segments which are guaranteed to be completely in the range43 while (__sfirst != __slast) {44 __func(_Traits::__begin(__sfirst), _Traits::__end(__sfirst));45 ++__sfirst;46 }47 // iterate over the last segment48 __func(_Traits::__begin(__sfirst), _Traits::__local(__last));49}50 51_LIBCPP_END_NAMESPACE_STD52 53#endif // _LIBCPP___ALGORITHM_FOR_EACH_SEGMENT_H54