title: structures and pointers error: dereferencing pointer to incomplete type
body: <p>ok I have three structs:</p>
  
  <pre><code>struct rss_s {
      Radio_types device_type;  // Its device_type which is defined by the typedef above Radio_Types
      char * device_info;   // some thing about the radio NAV/COM/etc.
      char * device_model;      // the Manufactures part/model number.
      char * device_serial;     // the device's serial number..
      int power_48v;        // power to the unit..
      int power_400hz;
      int panel_lamps;      // turn off or on the Panel Lamps only
      void * radio_info;
  
      struct radio_s_C614L8
      {
          loopsw_614L8 loop_sw_614L8;  this is an emum
          modesw_614L8 mode_sw_614L8;  this is an emum
          int sw_band;
          int sw_bfo;
          int meter;
          tuner *Tuner;
          int tuners;
      };
  
      typedef struct tuner_s
      {
          char *device_name;      // OS NAME
          int frequency[tuned];
          int power;
          int dial_lamp;
          void * back_radio;      // back-link to radios[n]
          void * back_info;       // back-link to radio_xxxx
          int fd[];
      } tuner;
  </code></pre>
  
  <p>I initialize them in main.c</p>
  
  <pre><code>// Radio 614L8
  static tuner tuner_C614L8[] = {{ .device_name = "/dev/TBD", }};
  static struct radio_s_C614L8  radio_C614L8 = { .Tuner = &amp;tuner_C614L8, .tuners =   DIM(tuner_C614L8) };
  
  static struct rss_s radios[] = {
  { .device_type  = C614L8,
    .device_info  = "ADF",
    .device_model = "614L8",
    .device_serial = "8384",
    .radio_info = &amp;radio_C614L8,},};
  </code></pre>
  
  <p>the above works with out errors....
  but when I try to initialize the the above radio... in my init_C614L8.c
  with the following code I get an error...
  <strong><em>error: dereferencing pointer to incomplete type</em></strong> in lines 4 &amp; 6</p>
  
  <pre><code>int init_C614L8( struct rss_s  * radios ){
  int rw, i;
  struct radio_s_614L8 * rad_info = radios -&gt; radio_info;
  tuner * this_tuner  = rad_info -&gt; Tuner;
      // Now we will loop over the sub_devices....
  for ( i = 0;  i &lt; rad_info -&gt; tuners; i++ ) {
  </code></pre>
  
  <p>I think I have to cast something but not shure
  Thanks</p>