More Details to Formatting User-Defined Types in C++20

// formatPoint.cpp

#include <format>
#include <iostream>
#include <string>

struct Point {
    int x{2017};
    int y{2020};
    int z{2023};
};

template <>
struct std::formatter<Point> : std::formatter<std::string> {
    auto format(Point point, format_context& context) const {
        return formatter<string>::format(
               std::format("({}, {}, {})", point.x, point.y, point.y), context);
  }
};

int main() {

    std::cout << '\n';

    Point point;

    std::cout << std::format("{:*<25}", point) << '\n';        // (1)
    std::cout << std::format("{:*^25}", point) << '\n';        // (2)
    std::cout << std::format("{:*>25}", point) << '\n';        // (3)

    std::cout << '\n';

    std::cout << std::format("{} {} {}", point.x, point.y, point.z) << '\n';  // (4)
    std::cout << std::format("{0:*<10} {0:*^10} {0:*>10}", point.x) << '\n';  // (5)

    std::cout << '\n';

}

template< class... Args >
std::string format( const std::locale& loc,
                    std::format_string<Args...> fmt, Args&&... args );

// internationalization.cpp

#include <chrono>
#include <exception>
#include <iostream>
#include <thread>

std::locale createLocale(const std::string& localString) {                         // (1)
  try {
    return std::locale{localString};       
  }
  catch (const std::exception& e) {
    return std::locale{""};
  }
}

int main() {

    std::cout << '\n';

    using namespace std::literals;

    std::locale loc = createLocale("de_DE");

    std::cout << "Default locale: " << std::format("{:}", 2023) << '\n';
    std::cout << "German locale:  " << std::format(loc, "{:L}", 2023) << '\n';    // (2)

    std::cout << '\n';

    std::cout << "Default locale: " << std::format("{:}", 2023.05) << '\n';
    std::cout << "German locale:  " << std::format(loc, "{:L}", 2023.05) << '\n'; // (3)

    std::cout << '\n';

    auto start = std::chrono::steady_clock::now();
    std::this_thread::sleep_for(33ms);
    auto end = std::chrono::steady_clock::now();

    const auto duration = end - start;

    std::cout << "Default locale: " << std::format("{:}", duration) << '\n';
    std::cout << "German locale:  " << std::format(loc, "{:L}", duration) << '\n'; // (4)

    std::cout << '\n';

    const auto now = std::chrono::system_clock::now();
    std::cout << "Default locale: " << std::format("{}\n", now);
    std::cout << "German locale:  " << std::format(loc, "{:L}\n", now);            // (5)

    std::cout << '\n';

}