C#: Require indexer on method parameter
<p>I'm writing a function which is a mapper from one type of object to another. The object which is passed in as a parameter of the Map method should have a string indexer to find the appropriate value in the object (or not). I don't really care if the mapper gets a Dictionary, DataRow, DataReader, etc. </p>

<p>Is there a way to specificy that the parameter passed to the method should implement a string indexer? I can't find anything like it. </p>

<p>I'll use reflection to cast the type to something usable if it's not possible, but I was wondering if there is proper way to handle this.</p>
