The array type
If you want to use it afterwards, ensure that you touchStorableArray after the last use of the pointer, so the array is not freed too early.
Construct a StorableArray from an arbitrary ForeignPtr. It is the caller's responsibility to ensure that the ForeignPtr points to an area of memory sufficient for the specified bounds.
The pointer to the array contents is obtained by withStorableArray. The idea is similar to ForeignPtr (used internally here). The pointer should be used only during execution of the IO action retured by the function passed as argument to withStorableArray.