syntax_data: {"ast_node_type":"other","tokens":[{"end":9,"kind":"keyword","start":0,"text":"{"}]}
source_snippet:         {
context_before:             && let ty::Slice(..) = ref_ty.kind()
context_after:             self.map.register_place(self.tcx.types.usize, place_index, TrackElem::DerefLen);