Self referencing closure

[acoustic eagle]

My goal is to let the user add a closure to a struct that accepts the struct as an input, as a way to add a sort of custom method.
Its purpose is to update the struct before that struct handles certain events. I plan to add a second one to run after events as well.

Here is a minimal example of the issue I have:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=f8119ccf560548ed681f39ece0e07711

And the error I get:

error[E0644]: closure/coroutine type that references itself
 --> src/main.rs:8:15
  |
8 |         func: |_| {}
  |               ^^^ cyclic type of infinite size
  |
  = note: closures cannot capture themselves or take themselves as argument;

Shouldn't this not be of infinite size since I took in the struct containing the closure by reference?
Is my only option to box it up and use dynamic dispatch?

[austere imp]

per the linked issue info, you can't have a closure type depend on itself

but also note that your function will be impossible to call, anyway

calling func means borrowing it, and since you have borrowed self.func, you won't be able to borrow all of self to create &mut MyStruct<F> to pass it to func