new ForeignPtr without finalizers

[Alastair Reid]

On Monday 09 June 2003 4:59 am, Ashley Yakeley wrote:
> OK, I just upgraded to GHC 6.0. How do I create a new ForeignPtr that
> doesn't have any finalizers?
>
>   newSimpleForeignPtr :: Ptr a -> IO (ForeignPtr a)
>   newSimpleForeignPtr ptr = ??

There is no direct way in the ffi.  You could define a dummy function in C:

  void dummy(HsPtr x) {}

and use:

   newSimpleForeignPtr :: Ptr a -> IO (ForeignPtr a)
   newSimpleForeignPtr ptr = newForeignPtr ptr dummy
   foreign import ccall "&" dummy :: FinalizerPtr
  

It looks like you're using an idiom we didn't think of when designing the 
library.  Can you explain what you're trying to do and whether you think we 
shoud provide direct support for newSimpleForeignPtr (which I'd be tempted to 
call newForeignPtr_).

--
Alastair Reid