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 <iostream> // for std::cout
#include <format> // for std::format
#include <print> // for std::print
#include <utility>
int main ()
{
std::tuple t{47, 0.4, "hi", '?'}; // 4-element tuple
std::cout << std::format("{}\n", t);
std::cout << std::format("{:_^25}\n", t);
std::println("{:_^25}\n", t);
std::println("default: {}", t);
std::println("{{:n}} : {:n}\n", t);
std::pair p{"val", 11}; // could also be a 2-elem tuple
std::println("default: {}", p);
std::println("{{:n}} : {:n}", p);
std::println("{{:m}} : {:m}\n", p);
}