$ cargo run Compiling traits-example v0.1.0 (file:///projects/traits-example) error[E0277]: `Point` doesn't implement `std::fmt::Display` --> src/main.rs:20:23 | 20 | impl OutlinePrint for Point {} | ^^^^^ `Point` cannot be formatted with the default formatter | = help: the trait `std::fmt::Display` is not implemented for `Point` = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead note: required by a bound in `OutlinePrint` --> src/main.rs:3:21 | 3 | trait OutlinePrint: fmt::Display { | ^^^^^^^^^^^^ required by this bound in `OutlinePrint` error[E0277]: `Point` doesn't implement `std::fmt::Display` --> src/main.rs:24:7 | 24 | p.outline_print(); | ^^^^^^^^^^^^^ `Point` cannot be formatted with the default formatter | = help: the trait `std::fmt::Display` is not implemented for `Point` = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead note: required by a bound in `OutlinePrint::outline_print` --> src/main.rs:3:21 | 3 | trait OutlinePrint: fmt::Display { | ^^^^^^^^^^^^ required by this bound in `OutlinePrint::outline_print` 4 | fn outline_print(&self) { | ------------- required by a bound in this associated function For more information about this error, try `rustc --explain E0277`. error: could not compile `traits-example` (bin "traits-example") due to 2 previous errors