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