The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <iostream>
#include <valarray>
using namespace std;
// print valarray
template <typename T>
void printValarray (const valarray<T>& va)
{
for (int i=0; i<va.size(); i++) {
cout << va[i] << ' ';
}
cout << endl;
}
int main()
{
// define two valarrays with ten elements
valarray<double> va1(10), va2(10);
// assign values 0.0, 1.1, up to 9.9 to the first valarray
for (int i=0; i<10; i++) {
va1[i] = i * 1.1;
}
// assign -1 to all elements of the second valarray
va2 = -1;
// print both valarrays
printValarray(va1);
printValarray(va2);
// print minimum, maximum, and sum of the first valarray
cout << "min(): " << va1.min() << endl;
cout << "max(): " << va1.max() << endl;
cout << "sum(): " << va1.sum() << endl;
// assign values of the first to the second valarray
va2 = va1;
// remove all elements of the first valarray
va1.resize(0);
// print both valarrays again
printValarray(va1);
printValarray(va2);
}