boxySplitTyConApp :: TyCon -- T :: k1 -> ... -> kn -> *
-> BoxyRhoType -- Expected type (T a b c)
-> TcM ([BoxySigmaType], -- Element types, a b c
boxySplitTyConApp :: TyCon -- T :: k1 -> ... -> kn -> *
-> BoxyRhoType -- Expected type (T a b c)
-> TcM ([BoxySigmaType], -- Element types, a b c