syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// - at any point, any or none of the patterns and guards seen so far may have been tested;
context_before:     /// checking. Specifically we want borrowck to think that:
context_after:     /// - after the match, any of the patterns may have matched.