syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"//"}]}
source_snippet: // FIXME(jswrenn) we'd likely benefit from specializing try_fold here.
context_after: impl<S: Copy, X: Iterator<Item = (Byte, S)>, Y: Iterator<Item = (Byte, S)>> Iterator