error[E0308]: mismatched types --> $DIR/macro-brackets.rs:11:21 | LL | id![static X: u32 = 'a';]; | ^^^ expected `u32`, found `char` | help: you can cast a `char` to a `u32`, since a `char` always occupies 4 bytes | LL | id![static X: u32 = 'a' as u32;]; | ++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.