Not sure why the author compares Rust's:

    println!("{} is {} years old", person.name, person.age);

with C++:

    cout << person.name << " is " << unsigned(person.age)
         << " years old" << endl;

... while C++ actually has:

    println("{} is {} years old", person.name, person.age);

essentially identical to Rust. See: https://en.cppreference.com/w/cpp/io/println