syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Non-`default` ("final") types are always projected. This is necessary in
context_before:     /// We also refuse to project any associated type that is marked `default`.
context_after:     /// general for soundness of specialization. However, we *could* allow projections