syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Returns `true` if this represents the generic parameters of the form `[?0, ?1, ?2]`,
context_before: impl<'tcx> IsIdentity for CanonicalUserType<'tcx> {
context_after:     /// i.e., each thing is mapped to a canonical variable with the same index.