error: must have type of `&mut Self::Context` as first argument --> tests/ui/fail/fn-invalid-context-03.rs:7:12 | 7 | fn foo(ctx: &mut i32) {} | ^^^^^^^^^^^^^ error: since Context is defined here --> tests/ui/fail/fn-invalid-context-03.rs:5:20 | 5 | type Context = i32; | ^^^