error: This generic shadows the built-in type `u32` --> $DIR/builtin-type-shadow.rs:4:8 | LL | fn foo(a: u32) -> u32 { | ^^^ | = note: `-D clippy::builtin-type-shadow` implied by `-D warnings` error[E0308]: mismatched types --> $DIR/builtin-type-shadow.rs:5:5 | LL | fn foo(a: u32) -> u32 { | --- expected `u32` because of return type LL | 42 | ^^ expected type parameter, found integer | = note: expected type `u32` found type `{integer}` = help: type parameters must be constrained to match other types = note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0308`.