The following code example is taken from the book
C++20 - The Complete Guide
by Nicolai M. Josuttis,
Leanpub, 2021
The code is licensed under a
Creative Commons Attribution 4.0 International License.
#include "always40.hpp"
#include <format>
#include <iostream>
template<>
struct std::formatter<Always40>
{
// parse the format string for this type:
constexpr auto parse(std::format_parse_context& ctx) {
return ctx.begin(); // return position of } (hopefully there)
}
// format by always writing its value:
auto format(const Always40& value, std::format_context& ctx) const {
return std::format_to(ctx.out(), "{}", value.getValue());
}
};