Currently, you use bumpalo, which is a reasonable choice, but you can achieve much the same end result via Box::leak.
At the moment, there's no particular reason to do this aside from eliminating the dependency, and I did it by hand when reducing the binom.v extraction into a compiletest for rustc.
However, if you arrived at a point where you had a proof that this was the last remaining reference, you could coerce the reference to a pointer, then cast_mut and upgrade it to the original Box via Box::from_raw, so it can be deallocated. This is something a simple bump allocator would not meaningfully facilitate.
Currently, you use bumpalo, which is a reasonable choice, but you can achieve much the same end result via
Box::leak.At the moment, there's no particular reason to do this aside from eliminating the dependency, and I did it by hand when reducing the binom.v extraction into a compiletest for rustc.
However, if you arrived at a point where you had a proof that this was the last remaining reference, you could coerce the reference to a pointer, then
cast_mutand upgrade it to the original Box viaBox::from_raw, so it can be deallocated. This is something a simple bump allocator would not meaningfully facilitate.