title: Multidimensional std::array
body: <p>In C++, how do I create a multidimensional <code>std::array</code>? I've tried this:</p>
  
  <pre><code>std::array&lt;std::array&lt;int, 3&gt;, 3&gt; arr = {{5, 8, 2}, {8, 3, 1}, {5, 3, 9}};
  </code></pre>
  
  <p>But it doesn't work. What am I doing wrong and how do I fix this?</p>