title: How to convert an object instance to shared_ptr instance
body: <p>Suppose I had two shared_ptr types such as</p>
  
  <pre><code>boost::shared_ptr&lt;ObjA&gt; sptrA;
  boost::shared_ptr&lt;ObjB&gt; sptrB;
  </code></pre>
  
  <p>Now suppose that <code>sptrA-&gt;SomeMethod()</code> returned a simple ObjB type (not a shared ptr). Is it possible for me to store that type somehow in sptrB ? So that I could do something like this so that the returned type instance is automatically converted to boost_shared ptr</p>
  
  <pre><code>sptrB = sptrA-&gt;SomeMethod(); 
  </code></pre>
  
  <p>I asked this question just of curiosity and whether it is possible or not ?</p>