syntax_data: {"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // it cannot be const in fewer cases than the parent impl).
context_before:     // and it must not be *more restrictive* than the parent impl (that is,
context_after:     if tcx.is_conditionally_const(parent_impl_def_id) {