title: std::vector emplace_back implementation
body: <p>The push_back function that I implemented:</p>
  <pre><code>void push_back(T&amp; num) {
      my_vec[index] = num;
      index++;
  }
  </code></pre>
  <p>And the emplace_back function:</p>
  <pre><code>template&lt;class... Args&gt;
  void emplace_back(Args&amp;&amp;... args) {
      push_back(T(std::forward&lt;Args&gt;(args)...));
  }
  </code></pre>
  <p>Do you see any problem with this? If yes then could you please tell me</p>
  <p>Also, please let me know how does this work?</p>
  <p>Please note: the emplace_back is not my implementation, I took it from other questions as I was looking for a way to implement my own emplace_back.</p>