Macro macro_helper::as_mut_ref_token

as_mut_ref_token!() { /* proc-macro */ }

Ensures that the reference or identifier passed is mutable and changes it if is not.

Typically useless because inside macros it ignores the namespace of the tokens captured by input and returns one that doesn't have always a declared identifier.This will change if the hygiene of the procedural macros is sync with the by-example ones.