{"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"ty::Dynamic(data,"}]}
                            ty::Dynamic(data, _, ty::Dyn) => mk_dyn_vtable(data.principal()),
                            ty::Slice(_) | ty::Str => tcx.types.usize,
                            _ => bug!("TyAndLayout::field({:?}): not applicable", this),