syntax_data: {"ast_node_type":"variable","tokens":[{"end":32,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let var_ty = ty;
context_before:                 // x's type, which is &T, where we want T (the type being matched).
context_after:                 if let hir::ByRef::Yes(_) = mode.0 {