Missing APIs from the types we cover (APIs have been added after this formalization was done)
- Structural conversion for slices. The matching operations in our model would be
&mut Cell<(A, B)>->&mut (Cell<A>, Cell<B>)and&Cell<(A, B)>->&(Cell<A>, Cell<B>)(both being NOPs).- Turns out to be very hard! The way we currently associate NA-masks with locations is in conflict with this. The invariant for the entire cell gets allocated "on" the first location of the cell, so when we do splitting the 2nd projection has no way to access it...
- Something like the example from rust-lang/unsafe-code-guidelines#168 (comment)