invalid conversion

m.dehghan · 07-28-2011, 04:31 AM

I am writing a function, and I'm getting the error "invalid conversion from 'void(*)(u_char* , u_int , void* )' to 'void(*)(tuple*,u_char*,u_int,void*)
Any help would be appreciated.

dwhitney67 · 07-28-2011, 05:18 AM

You haven't supplied enough information for anyone to truly point out the error in your code. However, below is a sample program that perhaps you can use to figure out where you went wrong with your programming.

Code:

#include <stdio.h>

typedef unsigned int  u_int;
typedef unsigned char u_char;

typedef struct
{
  u_int x, y, z;
} tuple;

typedef void (*Function)(tuple*, u_char*, u_int, void*);

void myFunction(tuple* param1, u_char* param2, u_int param3, void* param4)
{
   printf("I'm here!\n");
}

void otherFunction(Function f)
{
   tuple t;
   u_char uc;
   u_int  ui;
   void*  v;

   f(&t, &uc, ui, v);
}

int main(void)
{
   // passing function to another function
   otherFunction(&myFunction);

   // declaring a function pointer
   Function f = &myFunction;

   tuple t;
   u_char uc;
   u_int  ui;
   void*  v;

   f(&t, &uc, ui, v);

   return 0;
}