defile!() { /* proc-macro */ }Expand description
Remove macro metavar ungrouping in the given tokens, otherwise, pass them through.
Usage
Wrap the whole expansion (containing the call to the submacro) within this
macro, and prefix the metavariables you wish to ungroup with @.
If you need to emit an @ sigil (be it for the helper macro, or for actual
Rust syntax), simply escape the sigil by doubling it: @@.