<valarray>
Defines the template class valarray and numerous supporting template classes and functions.
For a list of all members of this header, see <valarray> Members.
#include <valarray>
Remarks
These template classes and functions are permitted unusual latitude in the interest of improved performance. Specifically, any function returning type valarray<T1> may return an object of some other type T2. In that case, any function that accepts one or more arguments of type valarray<T2> must have overloads that accept arbitrary combinations of those arguments, each replaced with an argument of type T2.
See Also
Reference
Thread Safety in the Standard C++ Library