title: Unable to find numeric literal operator ‘operator"" x0’
body: <p>I 'm reading the protocol specification that it explain <code>byte 0 : 0b0000001x if line Available.</code>
  So, I must create packet according to this doc, but I don't know how to assign 0b0000001x  to the variable in C.
  I have :</p>
  
  <pre><code>unsigned char * payload;
  payload[0] = 0b0000001x;
  </code></pre>
  
  <p>But I get the following error:</p>
  
  <blockquote>
    <p>error: unable to find numeric literal operator ‘operator"" x0’</p>
  </blockquote>