LL | fn foo(x: &dyn std::fmt::Display) {}
| ^ help: if this is intentional, prefix it with an underscore: `_x`
-warning: function is never used: `foo`
+warning: function `foo` is never used
--> $DIR/display-output.rs:13:4
|
LL | fn foo(x: &dyn std::fmt::Display) {}