title: c warning: 'struct' tag used in naming
body: <p>My code works on the face of it, but IMHO, warnings are a runtime error in waiting.</p>
  
  <p>Arduino, Slober 4.3.1 compile warning</p>
  
  <p>Much searching to no avail :(</p>
  
  <p>Is it unsafe to let this go?</p>
  
  <blockquote>
  <pre><code>warning: 'struct' tag used in naming 'union frame_t' [-fpermissive]  struct frame_t rxFrame;
          ^~~~~~~ ..\Array_struct_strncpy.ino:3:7: note: 'union frame_t' was previously declared here     union frame_t  // 4 byte comms frame
  </code></pre>
  </blockquote>
  
  <pre><code>union frame_t  // 4 byte comms frame
  {
      byte bytes[4]; // access as an array
      struct         // access by parts
      {
          byte sof;  // frame byte 0
          struct     // frame byte 1
          {
              byte adr: 5;
              byte opc: 2;
              byte vok: 1;
          };
          union
          {
              byte val; // frame byte 2 = value
              struct    // frame byte 2 = commands
              {
                  byte cmd1: 5;
                  byte cmd2: 3;
              };
          };
          byte crc; // frame byte 3
      };
  };
  
  struct frame_t rxFrame; // &lt;&lt;&lt; warning?
  </code></pre>
  
  <p>Best regards
  Dave</p>