Alright, I see that there haven't been any real complaints about adding Control.Monad.ignore since I first posted on 10 June. (Although there was a lot of related-but-off-topic discussion.) Since then, Don Stewart has pointed out http://hackage.haskell.org/trac/ghc/ticket/3292 that there is a very similar function specified in the FFI standard http://www.cse.unsw.edu.au/~chak/haskell/ffi/ffi/ffise5.html#x8-350005.10 - 'void :: IO a -> IO ()'. I don't favor 'ignore' over 'void' to an extent significant enough to make that an issue. But it's no longer clear what to do. Do we move void with its current type to Control.Monad and have Foreign.Marshal.Error re-export it? Do we define void with the generalized Functor sig, and have F.M.E re-export with a restricted type sig? Do we simply use my ignore patch and define F.M.E.void = ignore (with the restricted type sig)? The specifics of what to do are unclear enough that I don't think there's consensus for what to do with void, even if we clearly want some sort of void/ignore in Control.Monad. -- gwern