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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