[Haskell-cafe] Re: allocation for "pure" FFI functions

Duncan Coutts writes:

It is exactly for this purpose that the Haskell FFI library includes unsafePerformIO. This is basically *the* legitimate use case for it, so you don't need to feel bad about it.

OK, thanks. Then this means my C type is a ForeignPtr, and each time I use it (even read-only) it looks like unsafePerformIO $ withForeignPtr $ \ p -> ... Meanwhile I think I found a nice example and explanation here: http://en.wikibooks.org/wiki/Haskell/FFI#Self-Deallocating_Pointers J.W.