| error[E0277]: the trait bound `for<'a> <_ as Yokeable<'a>>::Output: IsCovariant<'a>` is not satisfied |
| --> $DIR/issue-90950.rs:50:12 |
| | |
| LL | upcast(y) |
| | ------ ^ the trait `for<'a> IsCovariant<'a>` is not implemented for `<_ as Yokeable<'a>>::Output` |
| | | |
| | required by a bound introduced by this call |
| | |
| = help: the trait `IsCovariant<'a>` is implemented for `std::borrow::Cow<'a, T>` |
| note: this is a known limitation of the trait solver that will be lifted in the future |
| --> $DIR/issue-90950.rs:50:12 |
| | |
| LL | upcast(y) |
| | -------^- |
| | | | |
| | | the trait solver is unable to infer the generic types that should be inferred from this argument |
| | add turbofish arguments to this call to specify the types manually, even if it's redundant |
| note: required by a bound in `upcast` |
| --> $DIR/issue-90950.rs:27:42 |
| | |
| LL | fn upcast<Y>(x: Yoke<Y>) -> Yoke<Box<dyn IsCovariant<'static> + 'static>> where |
| | ------ required by a bound in this function |
| LL | Y: for<'a> Yokeable<'a>, |
| LL | for<'a> <Y as Yokeable<'a>>::Output: IsCovariant<'a> |
| | ^^^^^^^^^^^^^^^ required by this bound in `upcast` |
| |
| error: aborting due to 1 previous error |
| |
| For more information about this error, try `rustc --explain E0277`. |
