syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"Ok(ref"}]}
source_snippet:         Ok(ref val) if val != "0" => CtfeBacktrace::Capture,
context_before:         Ok(ref val) if val == "immediate" => CtfeBacktrace::Immediate,
context_after:         _ => CtfeBacktrace::Disabled,