Invalid user-defined conversion Error

[elifyoldas]

Hello

i try to compile main class which writed in read.md file.
i take invalid user-defined conversion error from this lines;

// Run async command with callback
connection.command({"PING"}, [](RedisClient::Response r) {
QVariant val = r.getValue(); // get value from response
// do stuff
});

The whole error : invalid user-defined conversion from 'main(int, char **)::<lambda(RedisClient::Response)>'to 'int'[-fpermissive] });

Thank you :)