title: C++ queue<string> initializer list with double curly braces
body: <p>From this question <a href="https://stackoverflow.com/questions/10293302/why-cant-i-construct-a-queue-stack-with-brace-enclosed-initializer-lists-c1">Why can&#39;t I construct a queue/stack with brace-enclosed initializer lists? (C++11)</a>, we know that it won't work by constructing a queue with single curly braces. Because queue is container adapter which does not have constructor with initializer list.</p>
  <p>However, why below approach will work? Does double curly braces call queue's constructor with container argument? So the inner curly brace <code>{&quot;hello&quot;}</code> is considered as a <code>vector&lt;string&gt;</code>?</p>
  <pre><code>    queue&lt;string&gt; q{{&quot;hello&quot;}}; //Question: why init with double curly braces?
  </code></pre>