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<int> coll{1, 2, 3, 4, 5, 6, 7, 8};
std::println("{}", coll);
// modify first five values:
for (auto& elem : coll | std::views::take(5)) {
elem = elem * elem; // OK
}
std::println("{}", coll);
// cannot modify first five values:
for (auto& elem : coll | std::views::take(5) | std::views::as_const) {
elem = elem * elem; // ERROR: elem is const
}
std::println("{}", coll);
}