MIXFUNCVOID

Message        <Context> compatibility of a pointer to void and a
               pointer to a function is not portable under the C
               standard.

Description    The C standard defines pointer to void as being
               assignment compatible only with pointers to object or
               incomplete types.  An implementation may represent
               function pointers in a way that cannot be stored in a
               pointer to void (or vice-versa).  Thus even an
               explicit cast between a function pointer and a
               pointer to void is not portable.

User Action    If a generic pointer to function is needed, declare a
               typedef for some pointer to function type, and always
               use explicit casts to assign to and from that type.