+\begin{code}
+addDataConStupidTheta :: InstOrigin -> DataCon -> [TcType] -> TcM ()
+-- Instantiate the "stupid theta" of the data con, and throw
+-- the constraints into the constraint set
+addDataConStupidTheta origin data_con inst_tys
+ | null stupid_theta = return ()
+ | otherwise = instStupidTheta origin inst_theta
+ where
+ stupid_theta = dataConStupidTheta data_con
+ tenv = zipTopTvSubst (dataConUnivTyVars data_con) inst_tys
+ inst_theta = substTheta tenv stupid_theta
+\end{code}
+