error[E0107]: function takes 0 generic arguments but 1 generic argument was supplied --> $DIR/issue-100154.rs:4:5 | LL | foo::<()>(()); | ^^^------ help: remove these generics | | | expected 0 generic arguments | note: function defined here, with 0 generic parameters --> $DIR/issue-100154.rs:1:4 | LL | fn foo(i: impl std::fmt::Display) {} | ^^^ = note: `impl Trait` cannot be explicitly specified as a generic argument error[E0277]: `()` doesn't implement `std::fmt::Display` --> $DIR/issue-100154.rs:4:11 | LL | foo::<()>(()); | ^^ `()` cannot be formatted with the default formatter | = help: the trait `std::fmt::Display` is not implemented for `()` = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead note: required by a bound in `foo` --> $DIR/issue-100154.rs:1:16 | LL | fn foo(i: impl std::fmt::Display) {} | ^^^^^^^^^^^^^^^^^ required by this bound in `foo` error: aborting due to 2 previous errors Some errors have detailed explanations: E0107, E0277. For more information about an error, try `rustc --explain E0107`.