error[E0308]: mismatched types --> $DIR/equality.rs:15:5 | LL | return 1_i32; | ----- expected because of this statement LL | } LL | 0_u32 | ^^^^^ expected i32, found u32 | = note: expected type `i32` found type `u32` error[E0277]: cannot add `impl Foo` to `u32` --> $DIR/equality.rs:24:11 | LL | n + sum_to(n - 1) | ^ no implementation for `u32 + impl Foo` | = help: the trait `std::ops::Add` is not implemented for `u32` error: aborting due to 2 previous errors Some errors occurred: E0277, E0308. For more information about an error, try `rustc --explain E0277`.