error[E0308]: mismatched types | |
--> $DIR/retslot-cast.rs:13:5 | |
| | |
LL | inner(x) | |
| ^^^^^^^^ expected trait `Iterator<Item = ()>`, found trait `Iterator<Item = ()> + Send` | |
| | |
= note: expected enum `Option<&dyn Iterator<Item = ()>>` | |
found enum `Option<&dyn Iterator<Item = ()> + Send>` | |
error: aborting due to previous error | |
For more information about this error, try `rustc --explain E0308`. |