title: How do I correctly pass, as argument, a literal integer as a void pointer, using its address as the integer’s actual value
body: <p>As an experiment:</p>
  
  <p>I have hypothetical function with signature: <code>void func(void *)</code>, where I have to pass an integer value, literally in the code: <code>func(42)</code>. <em>It must be done with a literal integer</em>.</p>
  
  <p>Is there a “right” way to pass a integer value, say, “hacked” as an address in a pointer (to address 0x2A for example), and the somehow convert it back to an integer (42 for the 0x2A example). All of this without unexpected behavior?</p>
  
  <p>In short: being able to convert a pointer address into an integer which will hold the number of the address.</p>