syntax_data: {"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let user_ty = user_ty.as_ref().map(|user_ty| {
context_before:                 let inferred_ty = expr.ty;
context_after:                     this.canonical_user_type_annotations.push(CanonicalUserTypeAnnotation {