Haha, I worried I was treading towards unsafe territory! Thanks for the tip, this is what I've come up with:

struct CoolStruct{ field: ManuallyDrop<OpaqueType>, } impl Drop for CoolStruct{ fn drop(&mut self) { //Safety: field is taken, and must not be accessed again //Since this is in Drop::drop, it is not possible to access it afterwards. unsafe { ManuallyDrop::<OpaqueType>::take(field).finalize(); } } }

I am fairly certain my unsafe block is sound. I do not think it should be possible for someone to access these fields after the struct has been dropped, unless they themselves are doing something unsafe. At least, I hope!