Static rustc_lint::builtin::MISSING_FRAGMENT_SPECIFIER

pub static  MISSING_FRAGMENT_SPECIFIER: &'static Lint

The missing_fragment_specifier lint is issued when an unused pattern in a macro_rules! macro definition has a meta-variable (e.g. $e) that is not followed by a fragment specifier (e.g. :expr).

This warning can always be fixed by removing the unused pattern in the macro_rules! macro definition.

Example

macro_rules! foo {
   ($e) => {}
}

{{produces}}

Explanation

The meta-variable ($e above) lacks a fragment specifier, which is a malformed input. It can be fixed by adding a fragment specifier.