Function main

07-Error Handling/code/expected.cpp:22–43

}

int main()
{
    auto process = [](std::string_view str) {
        std::print("str: {:?}, ", str);
        parse_number(str)
            .transform([](double val) {
                std::println("value: {}", val);
                return val;
            })
            .transform_error([](std::errc err) {
                if (err == std::errc::invalid_argument)
                    std::println("error: invalid input");
                else if (err == std::errc::result_out_of_range)
                    std::println("error: overflow");
                return err;
            });
    };

    for (auto src : { "42", "42abc", "meow", "inf" })
        process(src);
    return 0;
}