title: What is the meaning of operation in c
body: <p>I am trying to serialize PHP opcode. I am confused with code. Please check following code. What is the meaning of the code.</p>
  
  <p><code>(ptr) = (void*)((char*)(ptr) - (char*)script-&gt;mem)</code></p>
  
  <p><a href="https://github.com/php/php-src/blob/6aaab9adf7619c121c19701022aeb8d88f9c3bab/ext/opcache/zend_file_cache.c#L112" rel="nofollow noreferrer">https://github.com/php/php-src/blob/6aaab9adf7619c121c19701022aeb8d88f9c3bab/ext/opcache/zend_file_cache.c#L112</a></p>
  
  <p>How to serialize <code>op_array</code> ?</p>