This can be done without casts by using a union:
typedef struct A A;
typedef struct B B;
void processA(A *);
void processB(B *);
typedef union { void (*A)(A *); void (*B)(B *); } U;
U Ps[] = { {.A = processA}, {.B = processB} };
int main(void)
{
Ps[0].A(0); // 0 used for example; normally you would supply a pointer to an A.
Ps[1].B(0); // 0 used for example; normally you would supply a pointer to a B.
return 0;
}
You must call the function using the correct member name; this method only allows you to store one pointer or the other in each array element, not to perform weird function aliasing.
Another alternative is to use proxy functions that do have the type needed when calling with a parameter that is a pointer to char
and that call the actual function with its proper type:
typedef struct A A;
typedef struct B B;
void processA(A *);
void processB(B *);
typedef void (*processor_t)();
void processAproxy(char *A) { processA(A); }
void processBproxy(char *B) { processB(B); }
processor_t Ps[] = { processAproxy, processBproxy };
int main(void)
{
char *a = (char *) address of some A object;
char *b = (char *) address of some B object;
Ps[0](a);
Ps[1](b);
return 0;
}
I used char *
above since you stated you are using it, but I would generally prefer void *
.