X-Git-Url: https://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Data%2FHList%2FPrelude.hs;h=d50ad25e081c6e129442081d239f29b244f35543;hb=66d175582375d19adfa8747c9e1c468138d47583;hp=3a46616662132331d8479a57ee70692cf9eed6ef;hpb=000307857df5266907964aff4ecc9e118314fe3f;p=hs-rrdtool.git

diff --git a/Data/HList/Prelude.hs b/Data/HList/Prelude.hs
index 3a46616..d50ad25 100644
--- a/Data/HList/Prelude.hs
+++ b/Data/HList/Prelude.hs
@@ -342,4 +342,14 @@ instance TypeCast'' t a b => TypeCast' t a b
 instance TypeCast'' () a a
     where
       typeCast'' _ x = x
+
+
+class MemberT e l where
+    type Member e l
+
+instance MemberT e Nil where
+    type Member e Nil = False
+
+instance MemberT e (Cons e' l) where
+    type Member e (Cons e' l) = TypeEq e e' b => b
 -}
\ No newline at end of file