Comment by j on "Rust passing a boxed closure doesn't work because of sizedness"

I think Sized doesn't work because closures aren't sized in general. I've wondered in the past whether Rust should have a (sized) function trait for lambdas that don't capture any variables...

The weird thing though is that when I add +Sized, that's not the error I get. Instead it says only auto-traits can be used. Sized so I guess I learned today that Sized is not auto.

Generic might work (I assume you mean remove the Box?), but unfortunately in the real code the router is a struct field, so it should be sized (I don't want the struct to have a closure type parameter).

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