Method all

tests/lvalue_functor_example.cc:25–30

	user(int age, string name, double weight) : age(age), name(name), weight(weight) { }

    static std::vector<user> all(sqlite::database& db) {
	  builder<user, int, std::string, double> person_builder;
      db << "SELECT * FROM user;"
        >> person_builder;
      return std::move(person_builder.results); // move to avoid copying data ;-)
    };
};

int main() {