Re: Why does sizeOf Word64 = 4?

9 Nov 2003


      sön 2003-11-09 klockan 03.32 skrev Ben Escoto:
...
Hi, I'm trying to learn about Haskell's FFI (running 6.0.1 on linux)
and see the following weird behavior with ghci:
Prelude> :module Data.Word Foreign.Storable Foreign.Ptr
  Prelude Foreign.Ptr Foreign.Storable Data.Word> sizeOf nullPtr
  4
  Prelude Foreign.Ptr Foreign.Storable Data.Word> sizeOf
                                            (nullPtr :: Ptr Word64)
  4
Shouldn't "sizeOf nullPtr" return an error?  And sizeOf a Ptr Word64
should be 8 I think.
The size of a pointer is not the same as the size of what it points at.
On ia32 (x86) architectures, the size of a pointer is always 4 bytes (32
bits).

Regards,

	Martin

Re: Why does sizeOf Word64 = 4?

Martin Norbäck