This could be beside castPtr, castCharToCChar etc. ---- castAny :: (Storable a, Storable b) => a -> b castAny = unsafePerformIO . genericCast where genericCast :: (Storable a, Storable b) => a -> IO b genericCast v = return undefined >>= \r -> allocaBytes (max (sizeOf v) (sizeOf r)) $ \p -> poke p v >> if False then return r else peek (castPtr p) ---- GHCi: > let a = -1000 :: Int16 > castAny a :: Word16 --> 64536 > castAny a :: Ptr () 0xb4c2fc18 > castAny (castAny a :: Ptr ()) :: Int16 -1000 > let b = pi :: CLDouble > b 3.141592653589793 > castAny b :: CInt 1413754136 > castAny b :: Ptr () 0x54442d18 > castAny b :: CFloat 3.3702806e12 > castAny b :: Int8 24 At minimum, this is safer than 'unsafeCoerce'. What do you think? Best, Maurício