error[E0277]: the trait bound `X: Copy` is not satisfied
  --> $DIR/trait-impl-bound-suggestions.rs:14:52
   |
LL | struct ConstrainedStruct<X: Copy> {
   |                             ---- required by this bound in `ConstrainedStruct`
...
LL |     fn return_the_constrained_type(&self, x: X) -> ConstrainedStruct<X> {
   |                                                    ^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `X`
   |
help: consider further restricting type parameter `X`
   |
LL | trait InsufficientlyConstrainedGeneric<X=()> where X: Copy {
   |                                              ^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.