title: What dotnet collection class's items can be enumerated in "addition order" and retrieved via a key?
body: <p>I'm lead to believe that I cannot count on the order of items added to a dictionary for enumeration purposes.</p>
  
  <p><strong>Is there a class (generic if possible) to which items may be added with a key and which can be enumerated in addition order or which can be retrieved by key?</strong></p>
  
  <p>Clarification: I do not want to enumerate in Key Order. I want to enumerate in addition order. Which is to say that I want to be able to retrieve the items via enumeration on a FIFO ( first in first out) basis.</p>