question regarding oop

[Moritz]

Hello everyone,

Im new to the D language and have a question regarding a slightly 
advanced matter:

Im currently porting the code of a game Im writing to D, and right now 
Im working on the event handling (reacting to user input).
Since Im doing a strategy game, I have several menues and I need a way 
to connect a menu to the state my game is in, so when the player clicks 
somewhere, I can use the hashtable to determine which menu class should 
react.

I think an asossiative array is the way I should go, key would be the 
state my game is in and the value would be the corresponding Menu.
But since there are several different menu classes, I need some way to 
put them all in the value area of the array.

In C++, I could make them all inherit from a specific base class, and 
use the base class as data type for the value, so I effectively had 
different menues in one datatype in that hashmap.

How can I do this in D?