title: Match the size of std::array with parameter pack
body: <p>I have a function which can match <code>std::vector</code> and other containers well:</p>
  <pre class="lang-cpp prettyprint-override"><code>template &lt;typename T, typename... Rest,
            template &lt;typename, typename...&gt; class Container&gt;
  std::string DoSomethingOnContainer(Container&lt;T, Rest...&gt; vals) {
    // do something
  }
  </code></pre>
  <p>But it cannot match <code>std::array</code>, e.g. <code>std::array&lt;int, 10&gt;</code>. How to make the function also match  <code>std::array</code>?</p>
  <p>I am using c++17.</p>