syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:         /// Does this have `ConstKind::Placeholder`?
context_before:         const HAS_RE_PLACEHOLDER          = 1 << 7;
context_after:         const HAS_CT_PLACEHOLDER          = 1 << 8;