void resize( std::size_t count, T value = T() );
Resizes the valarray to contain count elements and assigns value to each element.
This functions invalidates all pointers and references to elements in the array.
Parameters
count - new size of the container value - the value to initialize the new elements with
Return value
(none).
Example
#include <valarray>
#include <iostream>
int main()
{
std::valarray<int> v{1,2,3};
v.resize(10);