title: unique_ptr operator=
body: <pre><code>std::unique_ptr&lt;int&gt; ptr;
  ptr = new int[3];                // error
  </code></pre>
  
  <pre>
  error C2679: binary '=' : no operator found which takes a right-hand operand of type 'int *' (or there is no acceptable conversion)
  </pre>
  
  <p>Why this is not compiled? How can I attach native pointer to existing unique_ptr instance?</p>