syntax_data: {"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                 if cfg!(debug_assertions) && matches!(pattern.kind, PatKind::DerefPattern { .. }) {
context_before:             | PatKind::DerefPattern { ref subpattern, borrow: ByRef::No } => {
context_after:                     // Only deref patterns on boxes can be lowered using a built-in deref.