Cannot portably call a static member function from C

[ben2ong2]

[ Example adapted from "C++ Gotchas", tutorial notes by
  Tom Cargill, p. 55 ]

/* ........................................................... */
/* callback.c                                                  */

typedef void (*fptr) (int, int)

void callback (fptr fp)
{
   (*fp) (111, 222);
}

// ...........................................................
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#include <iostream.h>


typedef void (*fptr) (int, int)

extern "C" void callback (fptr);


class C {
  public:
    static void f (int, int);
};

void C :: f (int a, int b)
{
    cout << "a=" << a << "b=" << b << endl;
}


int main ()
{
   callback ((fptr) &C::f);
   return 0;
}

// ...........................................................

The output from one system might be

a=111 b=222

The output from another system might be

a=222 b=111


ARM 7.4

   Since functions with different linkage may have different
   calling conventions, a linkage specification may have a major
   effect on pointers to functions.  In particular, C++ functions
   that do not have the ellipsis in their argument type may use a
   more efficient calling sequence than has traditionally been used
   for C functions.