Thread: How to use void* as an arguement?

I was wondering how qsort works with the combination of typeSize and void* input. I want to do arithmetic, but I'm not totally sure how to work this out...I'm thinking I could do a switch( typeSize ) and then convert to the appropriate type based on that, but I wouldn't be able to distinguish the difference between an int and an unsigned int.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

/*
	I want the input to be void*..not long.
*/
void hmmm( void *v, size_t typeSize )
{
	/*
		void*.c: In function `hmmm':
		void*.c:7: warning: dereferencing `void *' pointer
		void*.c:7: error: invalid use of void expression
	*/
	*v = 5;
}

int main( void )
{
	int n = 4;
	char c = 4;
	
	hmmm( &n, sizeof( n ) );
	hmmm( &c, sizeof( c ) );
	
	assert( n == 5 );
	assert( c == 5 );
	
	return 0;
}