I thought I'd leave this comment here:
I've been playing around with implementing an opt-in garbage collector as a library for C++.

I think this would be a pretty interesting tool for implementing more efficient functional data structures. Basically, there would be a opaque pointer type that would be produced by an allocation routine. Then root objects would be registered with the garbage collector. Each garbage-collectable type would have a reflection method that allowed the garbage collector to walk the object tree.

This way, things like bump-pointer allocation (allocations are only one addition operation!) and GC compaction could be implemented.

There's really no way to have garbage collection for all of C++. And we wouldn't want that. But, sometimes there's a much higher performance cost to certain abstractions in C++ than there would be with a garbage collector. I think this would quite a few useful use cases in a distributed task parallelism library I've been working on based around futures, IVars and LVars. I think there a lot of other embedded DSL use cases. While this isn't traditionally the domain of C++, I don't see why it shouldn't be...

Any thoughts?

Cheers,
Ben

Hy,

The list implementation is simple/nice but it imposes a limit on number of stored elements because of "additional effect" of recursive destruction. A garbage collector would be very nice indeed, without it I don't know if using a "production persistent List" is really possible.