//******************************************************** // The following code example is taken from the book // C++23 - The Complete Guide // by Nicolai M. Josuttis (www.josuttis.com) // http://www.cppstd23.com // // The code is licensed under a // Creative Commons Attribution 4.0 International License // http://creativecommons.org/licenses/by/4.0/ //******************************************************** #include #include #include #include struct MyInt { int value; MyInt(int i) : value{i} {} }; template<> struct std::formatter : std::formatter { auto format(const MyInt& obj, auto& ctx) const { return std::formatter::format(obj.value, ctx); // format value } }; int main() { MyInt mi = 42; std::println("MyInt: {}", mi); // prints: 42 std::println("MyInt vec: {}", std::vector{mi}); // prints: [42] }