troubleshooting Question

[C, C++, g++] Void pointer in arithmetics with warning in Ubuntu

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ichigokurosakiFlag for Afghanistan asked on
Linux OS DevCC++
8 Comments1 Solution1314 ViewsLast Modified:
If i compile my code with gcc under Ubuntu i get no warning and everything works good.

If i compile the same code with g++, i get this warning:

warning: pointer of type ‘void *’ used in arithmetic

This is the code:
 ssize_t read_num(int fd, void *data, size_t count) {
	ssize_t total = 0;

	while (count) {
		ssize_t rd = read(fd, data, count);
		if (rd < 0) {
			perror("read");
			return rd;
		} else {
			count -= rd;
			data += rd; <-- PROBLEM IS HERE
			total += rd;
		}
	}
	return total;
}
However, the program compiles and it works fine but i'd like to solve the warning.

I know that i cannot use void pointer in math in c++ because it is not a safe operation, but i do not know how to solve the warning.

Can you help me, please?
My g++ version is 4.5.2
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