struct Playing {}
struct Won {}
struct Lost {}

fn beginGame() -> Playing {
    Playing {}
}

fn winGame(p: Playing) -> Won {
    Won {}
}

fn loseGame(p: Playing) -> Lost {
    Lost {}
}


fn main() {
    let game0 = beginGame();
    let game1 = winGame(game0);
    let game2 = loseGame(game0);
}