{"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":")"}]}
    ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
        layout: Option<TyAndLayout<'tcx>>,
        let const_val = val.eval(*self.tcx, self.typing_env, span).map_err(|err| {