title: C++ ISO noexcept of noexcept
body: <p>In <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4296.pdf" rel="noreferrer">the C++ standard</a> there is the following definition:</p>
  
  <pre><code>template &lt;class T, size_t N&gt; void swap(T (&amp;a)[N], T (&amp;b)[N])
        noexcept(noexcept(swap(*a, *b)));
  </code></pre>
  
  <p>What does <code>noexcept(noexcept(swap(*a, *b)))</code> do?</p>