Why `wl_pointer::Event` is not `Copy` or `Clone`

[Aetf]

I'm piping the event to a broadcast channel, it'd be really handy if the event implements Clone.

I checked the source code and didn't see anything preventing that. Am I missing something?

[elinorbgr]

I don't think there is anything strictly preventing the event/request enums from being Clone indeed, the only point that would require some care is for messages that contain a RawFd, as cloning them mindlessly may cause some unexpected bugs.

[WhyNotHugo]

Note that FromRawFd::from_raw_fd is already unsafe, so cloning the fd is likely "not unsafe".

That said, pointer events don't pass any file descriptors, you're probably thinking of keyboard events.

[elinorbgr]

That said, pointer events don't pass any file descriptors, you're probably thinking of keyboard events.

Well, I'm thinking about all events. As this code is auto-generated by wayland-scanner it's kind of an all-or-nothing situation, either all event enums are Clone, or none are.

[ids1024]

Wayland-rs now generates Event enums with OwnedFd instead of RawFd, so it's definitely not possible to derive clone in that case.

Wayland-scanner could add Clone only if all events could be cloned, but that would be a backwards compat issue if a new protocol version added an event with an fd.

But I don't think there's any reason you can't use something like Arc<wl_pointer::Event> and send that over a broadcast channel.

So this doesn't really seem viable or necessary. As far as I can tell.