ranges/views2.cpp

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> values{1, 2, 3, 4, 5, 6, 7, 8};
  std::println("{}", values);

  // square first five values:
  for (int& i : values | std::views::take(5)) {
    i = i * i;
  }
  std::println("{}", values);

  // square even values:
  auto isEven = [] (const auto& val) { return val % 2 == 0; };
  for (int& i : values | std::views::filter(isEven)) {
    i = i * i;
  }
  std::println("{}", values);
}