Please NOT to ship unsized_local until deprecating bare trait objects


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 #![deny(bare_trait_objects)] default?


This comment would probably get more visibility in the tracking issue




thanks for the feedback, makes sense