title: Cannot create constexpr std::vector
body: <p>I can create <code>constexpr</code> std::array:</p>
  
  <pre><code>constexpr std::array&lt;int,5&gt; values {1,2,3,4,5};
  </code></pre>
  
  <p>It works fine. But I cannot create <code>constexpr</code> vector:</p>
  
  <pre><code>constexpr std::vector&lt;int&gt; vec = {1,2,3,4,5};
  </code></pre>
  
  <p>It gives me an error:</p>
  
  <p><code>the type 'const std::vector&lt;int&gt;' of constexpr variable 'vec' is not literal constexpr std::vector&lt;int&gt; vec = {1,2,3,4,5};</code></p>