The meta fragment specifier is considered as a single TT.

4ad8c30
Opened by Léo Testard at 2019-12-25 17:29:43

At various locations of the FOLLOW sets analysis for macro_rules!, meta is considered as always matching a single TT. This is not the case: ident = ... and ident(...) are both valid metas.

That being said the only consequence of this is that meta can be followed by anything, and I think it's not unreasonable to assume that the syntax of meta will not be expanded in the future... But still, we might want to check that.

  1. I think it's not unreasonable to assume that the syntax of meta will not be expanded in the future

    It could happen.

    Alex Burka at 2016-06-01 15:07:43

  2. Triage: honestly, I'm not good enough with macros to know what exactly the details are here; it seems that #63764 expanded the syntax even with this roadblock.

    Steve Klabnik at 2019-12-25 17:29:43