syntax_data: {"ast_node_type":"other","tokens":[{"end":31,"kind":"keyword","start":0,"text":"assert_eq!("}]}
source_snippet:                     assert_eq!(
context_before:                     // Ensure that for niche encoded tags the discriminant coincides with the variant index.
context_after:                         layout.ty.discriminant_for_variant(tcx, idx).unwrap().val,