syntax_data: {"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"ty::Str"}]}
source_snippet:             ty::Str | ty::Slice(_) | ty::Dynamic(..) => match sizedness {
context_after:                 SizedTraitKind::Sized => unreachable!("tried to assemble `Sized` for unsized type"),