54 lines
2.0 KiB
C++
54 lines
2.0 KiB
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___ALGORITHM_FOR_EACH_SEGMENT_H
|
|
#define _LIBCPP___ALGORITHM_FOR_EACH_SEGMENT_H
|
|
|
|
#include <__config>
|
|
#include <__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___ALGORITHM_FOR_EACH_SEGMENT_H
|