The following code example is taken from the book
C++23 - The Complete Guide
by Nicolai M. Josuttis,
Leanpub, 2026
The code is licensed under a
Creative Commons Attribution 4.0 International License.
// raw code
#include <print>
#include <vector>
#include <ranges>
int main()
{
std::vector coll{1, 4, 7, 10};
// define view for even elements of coll:
auto even = [](int i){ return i%2 == 0;};
auto collEven = coll | std::views::filter(even);
// add just some debug output:
std::println("even: {}", collEven);
// modify underlying range:
coll[0] = 0;
// print collection and view:
std::println("coll: {}", coll);
std::println("even: {}", collEven);
}