title: Convert unsigned char array with int to unsigned char
body: <p>Can somebody help me out with below error. Shall I cast <code>len</code> before I try to pass <code>buf</code>?</p>
  
  <pre><code>int len=2;
  unsigned char tmp[len + 1];
  unsigned char * buf = &amp;tmp;
  </code></pre>
  
  <p>The error is:</p>
  
  <pre><code>error: cannot convert 'unsigned char (*)[(((unsigned int)((int)len)) + 1)]' to 'unsigned char*' in assignment
  </code></pre>