I never mentioned this as a requirement in my original post, but I think there is a key difference between your playground post and a
I have the following weird situation:
has some function that generates B's
and wants to send/callback on these B's
imports struct B;
does NOT import struct A;
imports A, B;
has function F;
calls function from crate Foo
If I am understanding the Playground example correctly, it seems that the location that generates the B's, needs to construct a
Map<...>, which implies it needs to import
A -- is that correct?
Again, I never mentioned this as part of the original post.