title: function prototype with multiple parameters including void
body: <p>I have a piece of software in which there is a function ie:</p>
  
  <p><code>void function_name(structure_t *param1, void *param2){code....}</code></p>
  
  <p>I am trying to create a function prototype for this function so it can be linked to another function that occurs before it. I have tried the below line with no success, it does not want to compile.</p>
  
  <p><code>void function_name(structure_t, void);</code></p>
  
  <p>I have this line below the associated structure but my guess is the problem is related to the void. The function itself takes the void *param2, which to be honest, confuses me but it works.</p>
  
  <p>The compiler gives the error message: "'void' must be the only parameter"</p>