Simon P. Jones wrote recently about that ghc-6.12 takes in account the elliplis in MkT {t1 = x, ..} when reporting about unused bindings. Now, here is the example: module TT where data T = T {t1, t2 :: Int} f d = x where T {t1 = x, ..} = d ghc-6.12.2 warns about unused value of t2. And for f (T {t1 = x, ..}) = x, it does not warn about this. Is this a bug? I use extensions: TypeSynonymInstances UndecidableInstances FlexibleContexts FlexibleInstances MultiParamTypeClasses OverlappingInstances RecordWildCards NamedFieldPuns ghc-options: -fno-warn-overlapping-patterns -fwarn-unused-binds -fwarn-unused-matches -fwarn-unused-imports -O0 , but the options can be simplified, of course. Regards, ----------------- Serge Mechveliani mechvel@botik.ru