Modify containers with std::transform

The std::transform() function is remarkably powerful and flexible. One of the more commonly deployed algorithms in the library, it applies a function or lambda to each element in a container, storing the results in another container while leaving the original in place.

Given its power, it's deceptively simple to use.

How to do it…

In this recipe, we will explore a few applications for the std::transform() function:

• We'll start with a simple function that prints the contents of a container:

  void printc(auto& c, string_view s = "") {
      if(s.size()) cout << format("{}: ", s);
      for(auto e : c) cout << format("{} ", e);
      cout << '\n';
  }

We'll use this to view the results of our transformations.

• In the main() function, let's declare a couple of vectors:

  int main() {...