syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                     for &elem in rest {
context_before:                 if let Some((_last, rest)) = tys.split_last() {
context_after:                         self.require_sized(elem, ObligationCauseCode::TupleElem);