I don't have a particular opinion on this proposal, but I did want to chime in to note that there are several other functions in base besides biteSizeMaybe, finiteBitSize, sizeOf, and alignment that take a dummy argument. The last time I checked, all of these functions also fit the bill [1]: * Data.Bits.isSigned :: Bits a => a -> Bool * Data.Data.dataTypeOf :: Data a => a -> DataType * GHC.Generics.datatypeName :: Datatype d => t d f a -> String * GHC.Generics.moduleName :: Datatype d => t d f a -> String * GHC.Generics.isNewtype :: Datatype d => t d f a -> Bool * GHC.Generics.packageName :: Datatype d => t d f a -> String * GHC.Generics.conName :: Constructor c => t c f a -> String * GHC.Generics.conFixity :: Constructor c => t c f a -> Fixity * GHC.Generics.conIsRecord :: Constructor c => t c f a -> Bool * GHC.Generics.selName :: Selector s => t s f a -> String * GHC.Generics.selSourceUnpackedness :: Selector s => t s f a -> SourceUnpackedness * GHC.Generics.selSourceStrictness :: Selector s => t s f a -> SourceStrictness * GHC.Generics.selDecidedStrictness :: Selector s => t s f a -> DecidedStrictness * Prelude.floatRadix :: RealFloat => a -> Integer * Prelude.floatDigits :: RealFloat => a -> (Int, Int) * Text.Printf :: PrintfArg a => a -> ModifierParser Ryan S. ----- [1] This list was taken from http://hackage.haskell.org/package/proxied-0.3/docs/Data-Proxied.html