class that is initialized becomes null when outside of function

[Flaze07]

On Monday, 9 July 2018 at 09:38:30 UTC, ag0aep6g wrote:
> The `win` you're creating in `init` is a function-local 
> variable. It ceases to exist when `init` returns. It's not 
> `this.win`.
>
> In `run`, you're accessing `this.win`. It's still null because 
> you never assigned anything there.
>
> So change `auto win = ...;` to `this.win = ...;` or simply `win 
> = ...;`.

oops, I forgot... haha what a silly mistake, thank you