Why not memory specific destructors?

[via Digitalmars-d]

On Monday, 5 May 2014 at 18:08:22 UTC, Frustrated wrote:
> So, instead of removing destructors why not have multiple 
> types? If the object is manually allocated then we can 
> guarantee the destructor will be called when the object is 
> free'ed.
>
> But basically, since they would be different types of 
> destructors there would be no confusion about when they would 
> or wouldn't be called.
>
> 1. GC destructors - Never called when the object is managed by 
> the GC. (or maybe one can flag certain ones to always be called 
> and the GC will respect that)
>
> 2. Manual memory management destructors - Always called when 
> the object is allocated by manually.
>
> 3. Others(ARC, etc) - Same principle.

I don't see a need to distinguish between all possible ways of 
memory management. The key distinction is whether it's reliable 
or not. RAII/scope and manual management are deterministic and 
reliable, tracing GC is not, and ARC only if cycles are 
disallowed.

Destructors of the first kind are usually called just destructors 
and are used for resource management, and the second kind are 
called finalizers. These are useful for implementing weak 
references, caching, and various other things where you don't 
require objects to be destroyed at a certain point in time, but 
still want to get notified when they are.