title: Produce std::tuple of same type in compile time given its length by a template argument
body: <p>In c++, how can I implement a function with an int template argument indicating the tuple length and produce a std::tuple with that length?</p>
  
  <p>E.g. </p>
  
  <pre><code>func&lt;2&gt;() returns std::tuple&lt;int, int&gt;();
  func&lt;5&gt;() returns std::tuple&lt;int, int, int, int, int&gt;().
  </code></pre>