To help you familiarize with the Generics.Collections unit, I wrote a nice chapter about it in the “Modern Pascal Introduction”. It’s a longer chapter, with 4 nice examples using containers from Generics.Collections.
In the related news: complete migration to Generics.Collections in Castle Game Engine is done 🙂 We now use Generics.Collections for all the purposes where we previously used the FGL and CastleGenericLists units. This brings us closer to Delphi compatibility, and it makes code better (Generics.Collections works with records out-of-the-box, it has a TDictionary with a much cleaner API, etc.)
Also, Michalis is back from vacations, with lots of new strength 🙂