Calling closures in a Vec

In rust one might want to have a list of closures, for example as a list of callbacks.

Maybe if we borrow f?

But then if we dereference f?

That’s not very helpful. Thanks to some friendly guys over at #rust at I found something which works:

A note is that the closure types must be &mut || and not &||.

In the end I think that the error messages could be more clear. But now we have a running example and all is well in the world!