Tracking issue for Weak::{weak_count, strong_count}

[jonas-schievink]

This issue tracks stabilization for 4 methods added in #56696:

• std::rc::Weak::{strong_count, weak_count}
• std::sync::Weak::{strong_count, weak_count}

[bdonlan]

Although these were added for testing, it is occasionally useful to have a way to probe optimistically for whether a weak pointer has become dangling, without actually taking the overhead of manipulating atomics. Are there any plans to stabilize this?

[glebpom]

Having this stabilized would help. Currently, the only way to check if a weak pointer has become dangling is to call upgrade, which is by far expensive.

[stepancheg]

Currently, the only way to check if a weak pointer has become dangling is to call upgrade, which is by far expensive

Exactly my thoughts. So instead of stabilizing strong_count and weak_count we probably want fn has_strong(&self) -> bool.

[alexcrichton]

A concern has been listed for stabilization, so if those here interested in this would be willing to help out with that, that would be great!