Re: Type_Invariant and Finalize

[Simon Wright <simon@pushface.org>]

Natasha Kerensikova <lithiumcat@instinctive.eu> writes:

> The latest example is a sorted array of non-null
> paccess-to-indefinite-type values, where the "sortedness" is a natural
> type inveriant, but in Finalize I release the memory using an instance
> of Unchecked_Deallocation.

I don't think these can be null-excluding access types, because you
can't instantiate Unchecked_Deallocation for such a type?

> Or should I prepare for it, e.g. with an explicit boolean record
> component that is False for the most of the lifetime of the object,
> until the first call to Finalize?

This approach is normal, if finalization isn't naturally idempotent.
Sometimes one can use an already-present access value which, if null,
means the object has already been finalized.