syntax_data: {"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let upvars = args.as_closure().tupled_upvars_ty();
context_before:                 // fn(&'a T) }`, as discussed in #25860.
context_after:                 return upvars.visit_with(self);