title: unable to include circular_buffer in structure
body: <p>i am new to cpp. I wish to put "boost::circular_buffer histpos(5);" with 5 spaces to store 5 elements inside a cpp structure as member.</p>
  
  <p>i try this :</p>
  
  <pre><code>typedef struct histposRecorder{
     int32_t track_id;
          boost::circular_buffer&lt;float&gt; histpos(5);
  
  }coRecord;
  </code></pre>
  
  <p>and i get this error :</p>
  
  <pre><code>error: expected identifier before numeric constant
          boost::circular_buffer&lt;float&gt; histpos(5);
  error: expected ‘,’ or ‘...’ before numeric constant
  </code></pre>
  
  <p>this is the circular_buffer website i am referring to:
  <a href="https://www.boost.org/doc/libs/1_49_0/libs/circular_buffer/doc/circular_buffer.html" rel="nofollow noreferrer">https://www.boost.org/doc/libs/1_49_0/libs/circular_buffer/doc/circular_buffer.html</a></p>
  
  <p>please show me how to solve it</p>
  
  <p>The reason i want to put it in structure because i will have a lot different copies of circular_buffer to store the velocities of different objects.</p>
  
  <p>Thanks in advance</p>