error: associated item referring to unboxed trait object for its own trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:4:13 | LL | trait A: Sized { | - in this trait LL | fn f(a: A) -> A; | ^ ^ | help: you might have meant to use `Self` to refer to the implementing type | LL | fn f(a: Self) -> Self; | ~~~~ ~~~~ error: associated item referring to unboxed trait object for its own trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:10:13 | LL | trait B { | - in this trait LL | fn f(b: B) -> B; | ^ ^ | help: you might have meant to use `Self` to refer to the implementing type | LL | fn f(b: Self) -> Self; | ~~~~ ~~~~ error: associated item referring to unboxed trait object for its own trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:16:20 | LL | trait C { | - in this trait LL | fn f(&self, c: C) -> C; | ^ ^ | help: you might have meant to use `Self` to refer to the implementing type | LL | fn f(&self, c: Self) -> Self; | ~~~~ ~~~~ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:4:13 | LL | fn f(a: A) -> A; | ^ | = note: `A` it is dyn-incompatible, so it can't be `dyn` help: use a new generic type parameter, constrained by `A` | LL | fn f(a: T) -> A; | ++++++ ~ help: you can also use an opaque type, but users won't be able to specify the type parameter when calling the `fn`, having to rely exclusively on type inference | LL | fn f(a: impl A) -> A; | ++++ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:4:19 | LL | fn f(a: A) -> A; | ^ | help: `A` is dyn-incompatible, use `impl A` to return an opaque type, as long as you return a single underlying type | LL | fn f(a: A) -> impl A; | ++++ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:10:13 | LL | fn f(b: B) -> B; | ^ | = note: `B` it is dyn-incompatible, so it can't be `dyn` help: use a new generic type parameter, constrained by `B` | LL | fn f(b: T) -> B; | ++++++ ~ help: you can also use an opaque type, but users won't be able to specify the type parameter when calling the `fn`, having to rely exclusively on type inference | LL | fn f(b: impl B) -> B; | ++++ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:10:19 | LL | fn f(b: B) -> B; | ^ | help: `B` is dyn-incompatible, use `impl B` to return an opaque type, as long as you return a single underlying type | LL | fn f(b: B) -> impl B; | ++++ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:16:20 | LL | fn f(&self, c: C) -> C; | ^ | = note: `C` it is dyn-incompatible, so it can't be `dyn` help: use a new generic type parameter, constrained by `C` | LL | fn f(&self, c: T) -> C; | ++++++ ~ help: you can also use an opaque type, but users won't be able to specify the type parameter when calling the `fn`, having to rely exclusively on type inference | LL | fn f(&self, c: impl C) -> C; | ++++ error[E0782]: expected a type, found a trait --> $DIR/dyn-incompatible-trait-should-use-self-2021-without-dyn.rs:16:26 | LL | fn f(&self, c: C) -> C; | ^ | help: `C` is dyn-incompatible, use `impl C` to return an opaque type, as long as you return a single underlying type | LL | fn f(&self, c: C) -> impl C; | ++++ error: aborting due to 9 previous errors For more information about this error, try `rustc --explain E0782`.