Simple memcpy implementation

mymemcpy.c

#include <stdio.h>
#include <string.h>

void* my_memcpy(void* destination, void* source, size_t num)
{
	int i;
	char* d = destination;
	char* s = source;
	for (i = 0; i < num; i++) {
		d[i] = s[i];
	}
	return destination;
}

int main()
{
	char str1[]="Humble Bundle is awesome.";
	char str2[26];
	char str3[10];

	void* r1 = my_memcpy(str2, str1, 5);

	printf("str2 is %s, r1 is %p\n", str2, r1);

	void* r2 = my_memcpy(str2, str1, 26);

	printf("str2 is %s, r2 is %p\n", str2, r2);

	//This will cause an overflow
	//void* r3 = my_memcpy(str3, str1, 26);
	//printf("str3 is %s, r3 is %p\n", str3, r3);

	return 0;
}

signature should be void* my_memcpy(void* destination, const void* source, size_t num)