error[E0277]: the trait bound `for<'b> &'b S: Trait` is not satisfied --> $DIR/imm-ref-trait-object-literal-bound-regions.rs:17:14 | LL | foo::(s); | -------- ^ the trait `for<'b> Trait` is not implemented for `&'b S` | | | required by a bound introduced by this call | = help: the trait `Trait` is implemented for `&'a mut S` = note: `for<'b> Trait` is implemented for `&'b mut S`, but not for `&'b S` note: required by a bound in `foo` --> $DIR/imm-ref-trait-object-literal-bound-regions.rs:11:20 | LL | fn foo(_: X) | --- required by a bound in this function LL | where LL | for<'b> &'b X: Trait, | ^^^^^ required by this bound in `foo` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.