syntax_data: {"ast_node_type":"other","tokens":[{"end":97,"kind":"keyword","start":0,"text":"ExprKind::Box"}]}
source_snippet:         ExprKind::Box { .. } => error(GenericConstantTooComplexSub::BoxNotSupported(node.span))?,
context_before:         }
context_after:         ExprKind::ByUse { .. } => {