I recently make a lot of mistakes by missing
impl in function signatures. Almost everytime I was protected by the fact that unsized values cannot appear in function signatures, either argument or return position.
For myself, I would turn on
#![deny(bare_trait_objects)] to gain more protection.
I think this could happen to others as well, so I guess unless we prohibited raw
Trait appear in function sigtures, stablizing
unsized_local would make things worse as we lost protections. Maybe when it lands it is a good time to also make