error[E0277]: the trait bound `X: Copy` is not satisfied --> $DIR/trait-impl-bound-suggestions.rs:14:52 | LL | fn return_the_constrained_type(&self, x: X) -> ConstrainedStruct { | ^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `X` | note: required by a bound in `ConstrainedStruct` --> $DIR/trait-impl-bound-suggestions.rs:8:29 | LL | struct ConstrainedStruct { | ^^^^ required by this bound in `ConstrainedStruct` help: consider further restricting type parameter `X` | LL | trait InsufficientlyConstrainedGeneric where X: std::marker::Copy { | ++++++++++++++++++++++++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.