title: Cast to a type from the type name as a string
body: <p>I have an existing base type and I would like to cast it to a derived type base upon the name of the type as a string, so something like this:</p>
  
  <pre><code>public void DoStuffInDerivedType(string derivedName) {
     (base as Type.GetType(derivedName)).DoThisThing();
  }
  </code></pre>
  
  <p>I'm pretty sure this can't be done but would be good to know for sure.  Thanks</p>
  
  <p>EDIT: I understand that I could construct the object using reflection from the type name but I want use an existing object.  And also I know this is generally a bad idea.  However I wanted to use this for a SpecFlow BDD Feature.</p>