error[E0277]: the trait bound `K: Tr` is not satisfied --> $DIR/issue-96810.rs:8:8 | LL | s: S, | ^^^^ the trait `Tr` is not implemented for `K` | note: required by a bound in `S` --> $DIR/issue-96810.rs:1:13 | LL | struct S(T::Assoc); | ^^ required by this bound in `S` help: consider restricting type parameter `K` | LL | struct Hoge { | ++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.