There seems to be bugs on the Chat example

[ealione]

There seems to be bugs on the Chat example

[gnattu]

I think the respective lines should use ref so that the branch does not take ownership of the event:

SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(mdns::Event::Discovered(ref list))) => {...}
SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(mdns::Event::Expired(ref list))) => {...}
SwarmEvent::Behaviour(MyBehaviourEvent::Gossipsub(gossipsub::Event::Message {
                    propagation_source: ref peer_id,
                    message_id: ref id,
                    ref message,
                })) => ...

[ealione]

That indeed fixes the issue.

[thomaseizinger]

The examples are compiled in CI so I am surprised that they would contain compile errors. Are you running them from within the workspace? Did you copy them to a new project?

See https://github.com/libp2p/rust-libp2p/actions/runs/7463218376/job/20307376998#step:6:756 for the latest successful build of the example in CI.

What version of Rust are you using? Can you paste the output of cargo check --package chat-example after checking out latest master?

[thomaseizinger]

I'll close this for now because it works in CI.

[gnattu]

@thomaseizinger, I can confirm that Rust 1.75.0 works both with and without ref. It seems that some versions of the borrow checker might not allow the direct use of the event in match cases.

Therefore, the example doesn't need to change if it's only targeting the current stable rust. However, if there are issues with a particular borrow checker, adding ref could serve as a workaround for the error.

[thomaseizinger]

Did you use edition 2021? I am pretty sure that this also works for Rust < 1.75 but there may have been changes across the editions.

Anyway, glad it is resolved!