error[E0277]: the trait bound `i32: Tr` is not satisfied --> $DIR/issue-84973-2.rs:11:9 | LL | foo(a); | --- ^ the trait `Tr` is not implemented for `i32` | | | required by a bound introduced by this call | note: required by a bound in `foo` --> $DIR/issue-84973-2.rs:7:11 | LL | fn foo(i: T) {} | ^^ required by this bound in `foo` help: consider mutably borrowing here | LL | foo(&mut a); | ++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.