error[E0204]: the trait `Copy` cannot be implemented for this type --> $DIR/missing-bound-in-manual-copy-impl-2.rs:16:18 | LL | struct Wrapper(T); | - this field does not implement `Copy` ... LL | impl Copy for Wrapper> {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | note: the `Copy` impl for `OnlyCopyIfDisplay` requires that `S: std::fmt::Display` --> $DIR/missing-bound-in-manual-copy-impl-2.rs:4:19 | LL | struct Wrapper(T); | ^ help: consider restricting type parameter `S` | LL | impl Copy for Wrapper> {} | +++++++++++++++++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0204`.