title: Create Dictionary item on the fly with operator[]
body: <p>Normally when you create a <code>Dictionary&lt;Tkey, TValue&gt;</code> you have to first go and add k/v pairs by calling add on the dictionary itself.</p>
  
  <p>I have a <code>Dictionary&lt;string, mycontainer&gt;</code> where <code>mycontainer</code> is a container of other objects.  I need to be able to add things to the mycontainer quickly so I thought maybe I can overload the subscript <code>operator[]</code> to create a <code>mycontainer</code> on the fly if it doesn't already exist and then allowing me to call add on it directly, as such:</p>
  
  <p><code>mydictionnary["SomeName"].Add(myobject);</code>  without explicitly having to go create mycontainer every time a container with the said name doesn't exist in the dictionary.</p>
  
  <p>I wondered if this is a good idea or should I explicitly create new mycontainer objects?</p>