So I get this error:
error: implementation of `Role` is not general enough
--> xtask\tests\expanded\successes\basic.rs:74:21
|
74 | let join_handle = ::tokio::task::spawn(event_loop);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Role` is not general enough
|
= note: `dyn basic::BasicRole` must implement `Role`
= note: ...but `Role` is actually implemented for the type `(dyn basic::BasicRole + 'static)`
error: implementation of `Role` is not general enough
--> xtask\tests\expanded\successes\basic.rs:74:21
|
74 | let join_handle = ::tokio::task::spawn(event_loop);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Role` is not general enough
|
= note: `(dyn basic::BasicRole + '0)` must implement `Role`, for any lifetime `'0`...
= note: ...but `Role` is actually implemented for the type `(dyn basic::BasicRole + 'static)`
With the following item relations:
pub trait Role: 'static + Sync + Send { ... }
pub trait BasicRole: 'static + Send + Sync { ... }
impl Role for dyn BasicRole {...}
pub trait Accepts<T> { ...}
// This trait isn't directly involved but things broke when I introduced it
impl Accepts<usize> for dyn BasicRole {}
struct Actor { ... }
impl BasicRole for Actor { ... }
This is very confusing to me, because searching for that error text brings up examples where the traits involved have lifetime bounds which are missing here. However, the call to spawn that is triggering the error has very complicated lifetimes involved. As best as I can reduce it, it looks like this:
pub fn start(...) -> /*... */ {
use ::std::sync::Arc;
use ::tokio::time::{sleep, Duration, Instant};
use ::tokio::{pin, select};
let (basic_role_input, mut basic_role_output) = unbounded_channel(); // The items for this channel are Send
let actor = Arc::new_cyclic(|weak| Actor {
this: weak.clone(),
basic_role: basic_role_input,
});
let stored_actor = Arc::clone(&actor);
let event_loop = async move {
let loop_lambda = async {
loop {
select! {
Some (msg) = basic_role_output . recv () => { /* ... */},
else => { break ; }
};
}
};
AssertUnwindSafe(loop_lambda).await
};
let join_handle = ::tokio::task::spawn(event_loop);
unimplemented!()
}
Can anyone suggest how to fix this or what other avenues I might investigate about where the problem is?