/*
 * Mention by name the class(es) defined herein and provide an executive
 * summary of the purposes and fucntionality of each.
 */

class WhatEver {
  public:
    Function1(...);
    /*
     * Give specfication of the function, mentioning each parm by name.
     */
   ...
}

Then in .c file, have only internal comments within functions as necessary to
desribe coding details.