std::rotate_copy

Since C++17

Header: <algorithm>

  1. Copies the elements from the range [first,last), to another range beginning at d_first in such a way, that the element *(n_first) becomes the first element of the new range and *(n_first - 1) becomes the last element.

# Declarations

template< class ForwardIt, class OutputIt >
OutputIt rotate_copy( ForwardIt first, ForwardIt n_first,
ForwardIt last, OutputIt d_first );

(constexpr since C++20)

template< class ExecutionPolicy,
class ForwardIt1, class ForwardIt2 >
ForwardIt2 rotate_copy( ExecutionPolicy&& policy,
ForwardIt1 first, ForwardIt1 n_first,
ForwardIt1 last, ForwardIt2 d_first );

(since C++17)

# Parameters

# Return value

Output iterator to the element past the last element copied.

# Example

#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
 
int main()
{
    std::vector<int> src{1, 2, 3, 4, 5};
    std::vector<int> dest(src.size());
    auto pivot = std::find(src.begin(), src.end(), 3);
 
    std::rotate_copy(src.begin(), pivot, src.end(), dest.begin());
    for (int i : dest)
        std::cout << i << ' ';
    std::cout << '\n';
 
    // copy the rotation result directly to the std::cout
    pivot = std::find(dest.begin(), dest.end(), 1);
    std::rotate_copy(dest.begin(), pivot, dest.end(),
                     std::ostream_iterator<int>(std::cout, " "));
    std::cout << '\n';
}

# See also