syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// in the context of the arm body. To avoid surfacing this distinction in
context_before:     /// the context of the guard expression, but will continue to map to a `T`
context_after:     /// the user source code (which would be a severe change to the language and