error[E0277]: the trait bound `A: Copy` is not satisfied --> $DIR/wf-enum-fields.rs:12:17 | LL | SomeVariant(IsCopy) | ^^^^^^^^^ the trait `Copy` is not implemented for `A` | note: required by a bound in `IsCopy` --> $DIR/wf-enum-fields.rs:7:17 | LL | struct IsCopy { | ^^^^ required by this bound in `IsCopy` help: consider restricting type parameter `A` | LL | enum SomeEnum { | +++++++++++++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.