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//===----------------------------------------------------------------------===//
//
// 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___CXX03___ALGORITHM_FOR_EACH_SEGMENT_H
#define _LIBCPP___CXX03___ALGORITHM_FOR_EACH_SEGMENT_H
#include <__cxx03/__config>
#include <__cxx03/__iterator/segmented_iterator.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
// __for_each_segment is a utility function for optimizing iterating over segmented iterators linearly.
// __first and __last are expected to be a segmented range. __func is expected to take a range of local iterators.
// Anything that is returned from __func is ignored.
template <class _SegmentedIterator, class _Functor>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
__for_each_segment(_SegmentedIterator __first, _SegmentedIterator __last, _Functor __func) {
using _Traits = __segmented_iterator_traits<_SegmentedIterator>;
auto __sfirst = _Traits::__segment(__first);
auto __slast = _Traits::__segment(__last);
// We are in a single segment, so we might not be at the beginning or end
if (__sfirst == __slast) {
__func(_Traits::__local(__first), _Traits::__local(__last));
return;
}
// We have more than one segment. Iterate over the first segment, since we might not start at the beginning
__func(_Traits::__local(__first), _Traits::__end(__sfirst));
++__sfirst;
// iterate over the segments which are guaranteed to be completely in the range
while (__sfirst != __slast) {
__func(_Traits::__begin(__sfirst), _Traits::__end(__sfirst));
++__sfirst;
}
// iterate over the last segment
__func(_Traits::__begin(__sfirst), _Traits::__local(__last));
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___CXX03___ALGORITHM_FOR_EACH_SEGMENT_H
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