std::valarray<T>::cshift (3) - Linux Manuals

std::valarray<T>::cshift: std::valarray<T>::cshift


std::valarray<T>::cshift - 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. The new position of each element is (i‚ąícount) mod s where i is the previous position and s is size().


count - number of positions to shift the elements by

Return value

The resulting valarray with circularly shifted elements.


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.
      * All functions accepting an argument of type const std::valarray&
        except begin() and end()
        (since C++11) should also accept the replacement type.
      * All functions accepting two arguments of type const std::valarray& should accept every combination of const std::valarray& and the replacement type.
      * The return type does not add more than two levels of template nesting over the most deeply-nested argument type.


// Run this code

  #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";


  1 2 3 4 5 6 7 8
  3 4 5 6 7 8 1 2

See also

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