Support for non-owning deferred_ptr

[ratchetfreak]

Will there be support for non-owning deferred_ptrs that will not prevent objects being destroyed (don't participate in the mark phase) but will get nulled when the object they refer to gets destroyed? Like the semantics of a weak pointer in garbage collection.

[hsutter]

Yes, I intend to add that eventually because it's natural to want a weak version of a strong (shared) pointer type.

I'll probably put it off for a while as it's lower on the priority list, but I'll keep this issue open as a reminder.

[lichray]

How about returning a shared_ptr with a customized dtor?

[hsutter]

How about returning a shared_ptr with a customized dtor?

@zhihao: shared_ptr is an owning strong pointer, not a non-owning weak pointer, so users would expect it to keep the object alive. Also, the layout is incompatible – flavors of either shared_ptr or weak_ptr wouldn’t work because copying either one tries to access a reference count control block which doesn’t exist. The reason a different pointer type than shared_ptr was needed is because shared_ptr doesn’t have the copying and destruction properties needed, and the deleter doesn’t support sufficient customization to try to shoehorn it in.

[lichray]

I see. I kind of want to save some types so that people can gain some homogeneity in containers etc. Well.

[hsutter]

Thanks again for this suggestion. For now I'm waiting for feedback and bug reports from actual use of the library, and deferring enhancements and optimizations until then but keeping them in the backlog.