Can I turn unsigned char into char and vice versa?

Question

I want to use a function that expects data like this:

void process(char *data_in, int data_len);

So it\'s just processing some bytes really

Answer 1

You really need to view the code to process() to know if you can safely pass in unsigned characters. If the function uses the characters as an index into an array, then no, you can't use unsigned data.