std::valarray<T>::cshift

From cppreference.com
< cpp‎ | numeric‎ | valarray
 
 
 
 
valarray<T> cshift( int count ) const;

Returns a new valarray of the same size with elements whose positions are shifted circularly by count elements.

A non-negative value of count shifts the elements circularly left count places and a negative value of count shifts the elements circularly right -count places.

Parameters

count - number of positions to shift the elements by

Return value

The resulting valarray with circularly shifted elements.

Notes

The function can be implemented with the return type different from std::valarray. In this case, the replacement type has the following properties:

Example

#include <iostream>
#include <valarray>
 
int main()
{
    std::valarray<int> v{1, 2, 3, 4, 5, 6, 7, 8};
 
    for (auto const& val : v)
        std::cout << val << ' ';
    std::cout << '\n';
 
    std::valarray<int> v2 = v.cshift(2);
 
    for (auto const& val : v2)
        std::cout << val << ' ';
    std::cout << '\n';
}

Output:

1 2 3 4 5 6 7 8 
3 4 5 6 7 8 1 2

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 618 C++98 the expression of the shifted elements
contains zero-division if size() is 0
describes the new positions
without using expressions

See also

zero-filling shift the elements of the valarray
(public member function)