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.
| count | - | number of positions to shift the elements by |
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:
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. begin() and end() (since C++11) should also accept the replacement type. #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
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 |
| zero-filling shift the elements of the valarray (public member function) |
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