error[E0271]: type mismatch resolving `<{integer} as Fun>::F<'_> == [u8]` --> $DIR/issue-74684-2.rs:23:5 | LL | bug(Box::new(x)); | ^^^ type mismatch resolving `<{integer} as Fun>::F<'_> == [u8]` | note: expected this to be `[u8]` --> $DIR/issue-74684-2.rs:10:18 | LL | type F<'a> = i32; | ^^^ note: required by a bound in `bug` --> $DIR/issue-74684-2.rs:13:28 | LL | fn bug<'a, T: ?Sized + Fun = [u8]>>(t: Box) -> &'static T::F<'a> { | ^^^^^^^^^^^^ required by this bound in `bug` error: aborting due to previous error For more information about this error, try `rustc --explain E0271`.