ranges/fromrange.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 <functional>
#include <ranges>

int main()
{
  std::vector coll{47, 11, 0, 8, 15, -11, 7, 42, 99};
  std::println("coll: {}", coll);

  // store all odd values negated in a new container:
  auto isOdd = [] (auto val) { return val % 2 != 0; };
  std::vector<int> vec{std::from_range,
                       coll | std::views::filter(isOdd)
                            | std::views::transform(std::negate{})};

  // print the container:
  std::println("vec:  {}", vec);
}