Negative Drop impls, Drop auto-trait and ImplicitDrop

[felix.s]

Personally, I would prefer a proposal that removes the need for negative reasoning about Drop entirely, such as the one discussed here:

Fixing the `Drop` trait bound

What would I intuitively expect the Drop trait to behave like: When copying values, there are three categories of types: Cannot be copied (no traits) Can be copied using used-defined code (implements Clone) Can be trivially copied with mem-copy (implements Copy which derives from Clone) For dropping the situation should be similar, with the equivalent categories: Cannot be dropped (linear types). Those currently do not exist in Rust. Can be dropped using user-defined code (implements Drop)…