title: filling a boost vector or matrix
body: <p>Is there a single-expression way to assign a scalar to all elements of a boost matrix or vector?  I'm trying to find a more compact way of representing:</p>
  
  <pre><code>boost::numeric::ublas::c_vector&lt;float, N&gt; v;
  for (size_t i=0; i&lt;N; i++) {
      v[i] = myScalar;
   }
  </code></pre>
  
  <p>The following do not work:</p>
  
  <pre><code>boost::numeric::ublas::c_vector&lt;float, N&gt; 
     v(myScalar, myScalar, ...and so on..., myScalar);
  
  boost::numeric::ublas::c_vector&lt;float, N&gt; v;
  v = myScalar;
  </code></pre>