std::reverse_copy
From cppreference.com
Defined in header
<algorithm>
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template< class BidirIt, class OutputIt >
OutputIt reverse_copy( BidirIt first, BidirIt last, OutputIt d_first ); |
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Copies the elements from the range [first, last)
to another range beginning at d_first
in such a way that the elements in the new range are in reverse order.
Behaves as if by executing the assignment *(d_first + (last - first) - 1 - i) = *(first + i) once for each non-negative i < (last - first)
If the source and destination ranges (that is, [first, last)
and [d_first, d_first+(last-first))
respectively) overlap, the behavior is undefined.
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[edit] Parameters
first, last | - | the range of elements to copy |
d_first | - | the beginning of the destination range |
Type requirements | ||
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BidirIt must meet the requirements of BidirectionalIterator .
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OutputIt must meet the requirements of OutputIterator .
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[edit] Return value
Output iterator to the element past the last element copied.
[edit] Possible implementation
template<class BidirIt, class OutputIt> OutputIt reverse_copy(BidirIt first, BidirIt last, OutputIt d_first) { while (first != last) { *(d_first++) = *(--last); } return d_first; } |
[edit] Example
Run this code
#include <vector> #include <iostream> #include <algorithm> int main() { std::vector<int> v({1,2,3}); for (const auto& value : v) { std::cout << value << " "; } std::cout << '\n'; std::vector<int> destiny(3); std::reverse_copy(std::begin(v), std::end(v), std::begin(destiny)); for (const auto& value : destiny) { std::cout << value << " "; } std::cout << '\n'; }
Output:
1 2 3 3 2 1
[edit] Complexity
Linear in the distance between first
and last
[edit] See also
reverses the order of elements in a range (function template) |
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(parallelism TS)
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parallelized version of std::reverse_copy (function template) |