Re: Generic formal access types

[Robert A Duff <bobduff@shell01.TheWorld.com>]

mheaney@on2.com (Matthew Heaney) writes:

> I think a bigger problem is that the declared pointer type doesn't
> turn off the storage pool.  If the designated type is T'Class, doesn't
> this drag a lot of extra run-time baggage?

I don't remember what Address_To_Access_Conversions says about pools,
and I'm too lazy to look it up.  Probably nothing.

In general, an access-to-T'Class type needs to worry about finalization,
because even if T has no finalization, some extension might.  I don't
think that introduces any overhead in the conversions, but a class-wide
allocator would have to check (probably at run time) whether the actual
type has any finalization, and if so, hook the object into some list of
to-be-finalized objects.  Did you have anything else in mind?

In my current project, we care a lot about storage management, so we
have a coding convention: *Every* access type must have "for
T'Storage_Pool use..." to indicate which pool, or "for T'Storage_Size
use 0;" to indicate that there are no allocators for that type, or a
comment saying why we're violating this rule.

- Bob