title: Assigning to a variable which was moved in right side of expression
body: <p>Is this undefined behavior or not?</p>
  
  <pre><code>std::unique_ptr&lt;T&gt; p = some_function();
  
  p = some_other_function(std::move(p));
  </code></pre>
  
  <p>I've read <a href="http://en.cppreference.com/w/cpp/language/eval_order" rel="nofollow noreferrer">http://en.cppreference.com/w/cpp/language/eval_order</a> but not found definitive answer there.</p>