41 lines
747 B
C++
41 lines
747 B
C++
#ifndef OSRM_GROUP_BY
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#define OSRM_GROUP_BY
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#include <algorithm>
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#include <utility>
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namespace osrm
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{
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namespace util
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{
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// Runs fn on consecutive items in sub-ranges determined by pred.
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//
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// Example:
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// vector<int> v{1,2,2,2,3,4,4};
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// group_by(first, last, even, print);
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// >>> 2,2,2
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// >>> 4,4
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//
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// Note: this mimics Python's itertools.groupby
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template <typename Iter, typename Pred, typename Fn>
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Fn group_by(Iter first, Iter last, Pred pred, Fn fn)
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{
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while (first != last)
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{
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first = std::find_if(first, last, pred);
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auto next = std::find_if_not(first, last, pred);
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(void)fn(std::make_pair(first, next));
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first = next;
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}
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return fn;
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}
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} // namespace util
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} // namespace osrm
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#endif
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