title: GCC Warning: pointer arithmetic with type void *
body: <p>I have to write a function, in C on Linux, to read or write generic data.</p>
  
  <p>I can read (or write) big data so i made a while using how many bytes I read.
  At the next call i, for example, read in the original pointer + how many bytes I read. But I don't know the type so I used a void * but gcc says: </p>
  
  <pre><code>membox.c: In function ‘myRW’:
  membox.c:301:22: warning: pointer of type ‘void *’ used in arithmetic [-Wpointer-arith]
  w = read(fd, data + (s*type) , len - s);
                    ^
  membox.c:308:23: warning: pointer of type ‘void *’ used in arithmetic [-Wpointer-arith]
  w = write(fd, data + (s*type) , len - s);
  </code></pre>
  
  <p>Can i do this? I should ignore this warnings?</p>