syntax_data: {"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                     // just take a shared reference to the matched place.
context_before:                     // The arm binding will be by value, so for the guard binding
context_after:                     let rvalue = Rvalue::Ref(re_erased, BorrowKind::Shared, binding.source);