On Monday, 5 May 2014 at 14:17:04 UTC, Orvid King via
Digitalmars-d wrote:
Also, the @nogc for destructors is specific to the current GC,
and is a limitation that isn't really needed were destructors
implemented properly in the current GC.
How does one implement destructors (described below) properly in
a garbage collector?
I'm a bit puzzled by the recent storm over destructors. I think
of garbage collected entities (classes in Java) as possibly
having "finalizers", and scoped things as possibly having
"destructors". The two concepts are related but distinct.
Destructors are supposed to be deterministic, finalizers by being
tied to a tracing GC are not. Java doesn't have stack allocated
objects, but since 1.7 has try-'with resources' and AutoCloseable
to cover some cases in RAII-like fashion. My terminology is from
this http://www.hpl.hp.com/techreports/2002/HPL-2002-335.html
IMO, since D has a GC, and stack allocated structs, it would make
sense to use different terms for destruction and finalization, so
what you really want is to properly implement finalizers in your
GC.
I'm a lot more reluctant to use classes in D now, and I'd like to
see a lot more code with @nogc or compiled with a the previously
discussed and rejected no runtime switch.
Interestingly, Ada finalization via 'controlled' types is
actually what we call destructors here. The Ada approach is
interesting, but I don't know if a similar approach would fit
well with D, which is a much more pointer intensive language.
