The following code example is taken from the book
C++17 - The Complete Guide
by Nicolai M. Josuttis,
Leanpub, 2017
The code is licensed under a
Creative Commons Attribution 4.0 International License.
#include <vector>
#include <iostream>
#include <algorithm>
#include <execution> // for the execution policy
int main()
{
std::vector<int> coll{0, 8, 15, 2, 3, 7, 42};
//...
// count elements with even value:
auto num = std::count_if(std::execution::par, // execution policy
coll.cbegin(), coll.cend(), // range
[](int elem){ // criterion
return elem % 2==0;
});
std::cout << "number of elements with even value: " << num << '\n';
}