| //===----------------------------------------------------------------------===// |
| // |
| // 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 |