9.4 KiB
[alg.reverse]
26 Algorithms library [algorithms]
26.7 Mutating sequence operations [alg.modifying.operations]
26.7.10 Reverse [alg.reverse]
`template constexpr void reverse(BidirectionalIterator first, BidirectionalIterator last); template<class ExecutionPolicy, class BidirectionalIterator> void reverse(ExecutionPolicy&& exec, BidirectionalIterator first, BidirectionalIterator last);
template<bidirectional_iterator I, sentinel_for S> requires permutable constexpr I ranges::reverse(I first, S last); template<bidirectional_range R> requires permutable<iterator_t> constexpr borrowed_iterator_t ranges::reverse(R&& r);
template<execution-policy Ep, random_access_iterator I, sized_sentinel_for S> requires permutable I ranges::reverse(Ep&& exec, I first, S last); template<execution-policy Ep, sized-random-access-range R> requires permutable<iterator_t> borrowed_iterator_t ranges::reverse(Ep&& exec, R&& r); `
Preconditions: For the overloads in namespace std,BidirectionalIterator meets the Cpp17ValueSwappable requirements ([swappable.requirements]).
Effects: For each non-negative integer i < (last - first) / 2, applies std::iter_swap, orranges::iter_swap for the overloads in namespace ranges, to all pairs of iterators first + i, (last - i) - 1.
Returns: last for the overloads in namespace ranges.
Complexity: Exactly (last - first)/2 swaps.
`template<class BidirectionalIterator, class OutputIterator> constexpr OutputIterator reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result); template<class ExecutionPolicy, class BidirectionalIterator, class ForwardIterator> ForwardIterator reverse_copy(ExecutionPolicy&& exec, BidirectionalIterator first, BidirectionalIterator last, ForwardIterator result);
template<bidirectional_iterator I, sentinel_for S, weakly_incrementable O> requires indirectly_copyable<I, O> constexpr ranges::reverse_copy_result<I, O> ranges::reverse_copy(I first, S last, O result); template<bidirectional_range R, weakly_incrementable O> requires indirectly_copyable<iterator_t, O> constexpr ranges::reverse_copy_result<borrowed_iterator_t, O> ranges::reverse_copy(R&& r, O result); `
Let N be last - first.
Preconditions: The ranges [first, last) and [result, result + N) do not overlap.
Effects: Copies the range [first, last) to the range [result, result + N) such that for every non-negative integer i < N the following assignment takes place:*(result + N - 1 - i) = *(first + i).
Returns:
-
result + N for the overloads in namespace std.
-
{last, result + N} for the overloads in namespace ranges.
Complexity: Exactly N assignments.
template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [random_access_iterator](iterator.concept.random.access#concept:random_access_iterator "24.3.4.13 Concept random_access_iterator [iterator.concept.random.access]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_sentinel_for [iterator.concept.sizedsentinel]")<I> S, [random_access_iterator](iterator.concept.random.access#concept:random_access_iterator "24.3.4.13 Concept random_access_iterator [iterator.concept.random.access]") O, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_sentinel_for [iterator.concept.sizedsentinel]")<O> OutS> requires [indirectly_copyable](alg.req.ind.copy#concept:indirectly_copyable "24.3.7.3 Concept indirectly_copyable [alg.req.ind.copy]")<I, O> ranges::reverse_copy_truncated_result<I, O> ranges::reverse_copy(Ep&& exec, I first, S last, O result, OutS result_last); template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [sized-random-access-range](range.refinements#concept:sized-random-access-range "25.4.6 Other range refinements [range.refinements]") R, [sized-random-access-range](range.refinements#concept:sized-random-access-range "25.4.6 Other range refinements [range.refinements]") OutR> requires [indirectly_copyable](alg.req.ind.copy#concept:indirectly_copyable "24.3.7.3 Concept indirectly_copyable [alg.req.ind.copy]")<iterator_t<R>, iterator_t<OutR>> ranges::reverse_copy_truncated_result<borrowed_iterator_t<R>, borrowed_iterator_t<OutR>> ranges::reverse_copy(Ep&& exec, R&& r, OutR&& result_r);
Let N be min(last - first, result_last - result), and let NEW_FIRST be first + (last - first) - N.
Preconditions: The ranges [first, last) and [result, result + N) do not overlap.
Effects: Copies the range [NEW_FIRST, last) to the range [result, result + N) such that for every non-negative integer i<N the following assignment takes place:*(result + N - 1 - i) = *(NEW_FIRST + i).
Returns: {last, NEW_FIRST, result + N}.
Complexity: Exactly N assignments.