std::valarray<T>::cshift

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

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:

• All const member functions of std::valarray are provided.
• std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.
• For every function taking a conststd::valarray<T>& except begin() and end()(since C++11), identical functions taking the replacement types shall be added;
• For every function taking two conststd::valarray<T>& arguments, identical functions taking every combination of conststd::valarray<T>& and replacement types shall be added.
• The return type does not add more than two levels of template nesting over the most deeply-nested argument type.

Example

#include <print>
#include <valarray>

int main()
{
    const std::valarray<int> v{1, 2, 3, 4, 5, 6, 7, 8};
    std::println("{}", v);
    std::println("{} <- 3", v.cshift(3));
    std::println("{} <- 11", v.cshift(11));
    std::println("{} -> 2", v.cshift(-2));
    std::println("{} -> 10", v.cshift(-10));
}

[1, 2, 3, 4, 5, 6, 7, 8]
[4, 5, 6, 7, 8, 1, 2, 3] <- 3
[4, 5, 6, 7, 8, 1, 2, 3] <- 11
[7, 8, 1, 2, 3, 4, 5, 6] -> 2
[7, 8, 1, 2, 3, 4, 5, 6] -> 10

Defect reports

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

See also