error[E0599]: no method named `f` found for unit type `()` in the current scope --> $DIR/trait_items.rs:17:24 | LL | fn f(&self) {} | - the method is available for `()` here ... LL | fn f() { ::baz::m!(); } | ----------- in this macro invocation ... LL | pub macro m() { ().f() } | ^ method not found in `()` | = help: items from traits can only be used if the trait is in scope = note: this error originates in the macro `::baz::m` (in Nightly builds, run with -Z macro-backtrace for more info) help: the following trait is implemented but not in scope; perhaps add a `use` for it: | LL + use foo::T; | error: aborting due to previous error For more information about this error, try `rustc --explain E0599`.