#include <string>

class user {
public:
    user(std::string const& name)
        : name_ { name }
    {
    }
    auto valid_name(std::string const& name) -> bool
    {
        return name.length() < 20;
    }

private:
    std::string name_;
};

auto main() -> int
{
    auto n = std::string { "Santa Clause" };
    auto u = user { n };
    if (u.valid_name(n)) {
        user user1 { n };
    }
}