| error[E0277]: `U` doesn't implement `std::fmt::Debug` |
| --> $DIR/derive-debug.rs:11:36 |
| | |
| 7 | #[derive(Derivative)] |
| | - help: consider further restricting type parameter `U`: `, U: std::fmt::Debug` |
| ... |
| 11 | #[derivative(Debug(format_with="std::fmt::Debug::fmt"))] |
| | ^^^^^^^^^^^^^^^^^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug` |
| | |
| = help: the trait `std::fmt::Debug` is not implemented for `U` |
| = note: required because of the requirements on the impl of `std::fmt::Debug` for `&U` |
| = note: required by `std::fmt::Debug::fmt` |