Hi! I've been trying to use the C library FMOD in Haskell for about an hour now. The first test was the simple FSOUND_Init(int,int,uint) function which I got working by doing the following: foreign import ccall "fmod.h FSOUND_Init" fsound_Init :: CInt -> CInt -> CUInt -> IO CChar Which appeared to work just fine (the call went through, and I got sensible return values). Then I wanted to play some music so I tried to bring in the function FMUSIC_LoadSong which has the following C prototype (copy-pasted from the API): FMUSIC_MODULE * F_API FMUSIC_LoadSong( const char *name ); By doing this in Haskell: data MusicModule = MusicModule foreign import ccall "fmod.h FMUSIC_LoadSong" fmusic_LoadSong :: CString -> IO ForeignPtr MusicModule) I assume that this is how the ForeignPtr is meant to be used (with a dummy data type). Now if I compile this (under windows) with: ghc -fglasgow-exts --make FMODTest.hs -o test.exe -Llib -Iincludes -lfmod I get the following error: ./FMOD.hs:9: Unacceptable result type in foreign declaration: IO (ForeignPtr MusicModule) When checking declaration: foreign import ccall safe "static fmod.h &FMUSIC_LoadSong" fmusic_LoadSo ng :: Ptr CChar -> IO (ForeignPtr MusicModule) That's not a very helpful error message! Any ideas? /S -- Sebastian Sylvan +46(0)736-818655 UIN: 44640862