Function rustc_expand::mbe::macro_rules::try_match_macro
source · pub(super) fn try_match_macro<'matcher, T: Tracker<'matcher>>(
sess: &ParseSess,
name: Ident,
arg: &TokenStream,
lhses: &'matcher [Vec<MatcherLoc>],
track: &mut T
) -> Result<(usize, FxHashMap<MacroRulesNormalizedIdent, NamedMatch>), CanRetry>
Expand description
Try expanding the macro. Returns the index of the successful arm and its named_matches if it was successful,
and nothing if it failed. On failure, it’s the callers job to use track
accordingly to record all errors
correctly.