Re: [PATCH 0/4] baby step toward multi-target

[Doug Evans <dje@google.com>]

On Tue, Jul 29, 2014 at 10:45 AM, Tom Tromey <tromey@redhat.com> wrote:
> The more invasive branch took a different approach to target identity.
> Rather than the to_identity field, it split target_ops into a const
> vtable part and a payload part.  Then it aimed to require all targets to
> instantiate a new object.

Hi.  I'd like to understand this more.
By way of analogy, are you talking about something akin to RTTI, or
something else?
[How would the problem of target identity be solved if one went with
the "all targets instantiate a new object" approach?]

> This obviously has to touch a lot of code.  And, it runs into some
> difficulties where the target code must work with uninstantiated
> targets.

By way of analogy, is all such code akin to static methods?

> I don't think this is as much of an issue on the new branch.
> At least from what I recall the uninstantiated business isn't a big
> issue because this only affects a subset of methods, which can simply
> avoid looking at the payload.

Avoid looking at the payload how?
Do you mean said "methods" would get passed an argument they are
explicitly not supposed to touch?