{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
            let compute_size_skeleton = |t| SizeSkeleton::compute(t, tcx, typing_env).ok();
            // being applied (and we've got a problem somewhere).
            if !compute_size_skeleton(ty)?.same_size(compute_size_skeleton(field_ty)?) {