Unable to call UserData method for Arc<T>

[FelicitusNeko]

I'm trying to call a method on a struct with trait UserData, but the problem is that the struct is usually contained within an Arc. I've enabled userdata-wrappers, and I'm able to call functions for that struct, but attempting to call a method fails, as the method expects to receive &SMState as the second parameter, but is receiving &Arc<SMState> and crashing. Here's the code:

impl UserData for SMState {
  fn add_methods<M: mlua::UserDataMethods<Self>>(methods: &mut M) {
    // [...]
    methods.add_method("exit", |_lua, state, _: ()| {
      state.send(SMEvents::Terminate).ok();
      Ok(())
    });
    methods.add_async_function("sleep", async |_, msec: u64| {
      sleep(Duration::from_millis(msec)).await;
      Ok(())
    });
    // [...]
  }
}

And then running this Lua against it, with the UserData stored in the global sm:

sm.sleep(1000)
sm.exit()

sleep, as being a function, works fine and as intended (waits one second), but exit, as being a method, returns this panic:

thread 'tokio-rt-worker' (830137) panicked at src/luaenv.rs:250:32:
called `Result::unwrap()` on an `Err` value: CallbackError { traceback: "stack traceback:\n\t[C]: in field 'exit'\n\tsrc/luaenv.rs:237:8: in main chunk", cause: BadArgument { to: Some("SMState.exit"), pos: 1, name: Some("self"), cause: FromLuaConversionError { from: "missing argument", to: "userdata", message: None } } }

Is there a way to work around this, or do I ultimately need to get rid of the Arc?

[khvzak]

Lua has different syntax for calling methods. Try

sm:sleep(1000)
sm:exit()

Which is a sugar for:

sm.sleep(sm, 1000)
sm.exit(sm)

[FelicitusNeko]

Oh dang, okay. I think this is information I didn't know about Lua.