ae0ab14716
Cleanup to simplify code by using common terms like _first_ and _last_ in context of predicate applying in a range just like we do for spans and range containers. Pull Request: https://projects.blender.org/blender/blender/pulls/130380
59 lines
1.7 KiB
C++
59 lines
1.7 KiB
C++
/* SPDX-FileCopyrightText: 2024 Blender Authors
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*
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* SPDX-License-Identifier: GPL-2.0-or-later */
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#pragma once
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/** \file
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* \ingroup bli
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*/
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#include <algorithm>
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#include "BLI_utildefines.h"
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namespace blender::binary_search {
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/**
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* Find the index of the first element where the predicate is true. The predicate must also be
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* true for all following elements. If the predicate is false for all elements, the size of the
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* range is returned.
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*/
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template<typename Iterator, typename Predicate>
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static int64_t first_if(Iterator begin, Iterator end, Predicate &&predicate)
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{
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return std::lower_bound(begin,
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end,
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nullptr,
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[&](const auto &value, void * /*dummy*/) { return !predicate(value); }) -
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begin;
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}
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/**
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* Find the index of the last element where the predicate is true. The predicate must also be
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* true for all previous elements. If the predicate is false for all elements, the -1 is returned.
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*/
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template<typename Iterator, typename Predicate>
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static int64_t last_if(Iterator begin, Iterator end, Predicate &&predicate)
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{
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return std::upper_bound(begin,
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end,
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nullptr,
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[&](void * /*dummy*/, const auto &value) { return !predicate(value); }) -
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begin - 1;
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}
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template<typename Range, typename Predicate>
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int64_t first_if(const Range &range, Predicate &&predicate)
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{
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return first_if(range.begin(), range.end(), predicate);
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}
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template<typename Range, typename Predicate>
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int64_t last_if(const Range &range, Predicate &&predicate)
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{
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return last_if(range.begin(), range.end(), predicate);
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}
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} // namespace blender::binary_search
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