Is this kind of enum possible?

consider the following where a C (not C++) struct supports function ptrs. but C doesn't support inline defined functions nor constructor

supporting function pointers is probably key to enabling early development of C++ translated to C

#include <stdio.h>

void
myFunc (void) {
    printf ("%s:\n", __func__);
}

struct  My  {
    void (*f) (void);
};

struct My my;

int
main (void)
{
    my.f = myFunc;
    (*my.f)();
 
    return 0;
}