syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":"Some(ty::GenericArgKind::Const(ct))"}]}
source_snippet:             Some(ty::GenericArgKind::Const(ct)) => ct,
context_before:         let ct = match opt_ct {
context_after:             Some(kind) => self.const_param_expected(p, source_ct, kind),