pub static UNUSED_MACRO_RULES: &Lint
Expand description
The unused_macro_rules
lint detects macro rules that were not used.
Note that the lint is distinct from the unused_macros
lint, which
fires if the entire macro is never called, while this lint fires for
single unused rules of the macro that is otherwise used.
unused_macro_rules
fires only if unused_macros
wouldn’t fire.
§Example
#[warn(unused_macro_rules)]
macro_rules! unused_empty {
(hello) => { println!("Hello, world!") }; // This rule is unused
() => { println!("empty") }; // This rule is used
}
fn main() {
unused_empty!(hello);
}
{{produces}}
§Explanation
Unused macro rules may signal a mistake or unfinished code. Furthermore, they slow down compilation. Right now, silencing the warning is not supported on a single rule level, so you have to add an allow to the entire macro definition.
If you intended to export the macro to make it
available outside of the crate, use the macro_export
attribute.