error[E0423]: expected function, tuple struct or tuple variant, found trait `Foo` --> $DIR/issue-58022.rs:14:9 | LL | Foo(Box::new(*slice)) | ^^^ not a function, tuple struct or tuple variant error[E0790]: cannot refer to the associated constant on trait without specifying the corresponding `impl` type --> $DIR/issue-58022.rs:4:25 | LL | const SIZE: usize; | ------------------ `Foo::SIZE` defined here LL | LL | fn new(slice: &[u8; Foo::SIZE]) -> Self; | ^^^^^^^^^ cannot refer to the associated constant of trait error: aborting due to 2 previous errors Some errors have detailed explanations: E0423, E0790. For more information about an error, try `rustc --explain E0423`.