I see now that generics have improved a lot since latest release, we even have Delphi compatible syntax in Delphi mode. Recursive generic type is supported as well now (finally, I can continue my data structure library :)). Seeing these facts, what's the status of this feature now? Is it considered stable?--
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Is this true? I'd really like to see generics that with a mode where it is possible to say with the following syntax (compatible with Delphi):

type
  IDelegate<T> = interface
    procedure Add(const Handler: T);
    procedure Remove(const Handler: T);
  end;

And then specialize using the following syntax:

type
  INotifyDelegate = IDelegate<TNotifyEvent>;

Also, generic constraints are needed:

type
  TComponentTool<T: TComponent> = class(TObject)
  public
    procedure DoSomething(const C: T);
  end;

No, they are not stable. FPC generic syntax may change. But you can rely on delphi syntax (as we can't change it) with few limitations at the moment:
- no multiply generics with the same identifier and different amount of type parameters [1],
- no generic methods,
- no type constraints.

Also I may forgot something.

About [1] - in delphi it is possible to define different generics with the same identifier and different amount of type parameteres (even in the same unit). E.g.
TList = class ...; TList<T> = class ...; TList<T, TT> = class ...;

Then you can declare variables with any of that types. E.g.
var
   L: TList;
   LI: TList<Integer>;
   LIO: TList<Integer,TObject>

As I know Sven will work to support this and other missing generics features.

Best regards,
Paul Ishenin

Point 1 is already on a good way - with backwards compatible FPC syntax :) The only thing that still scares me are those nasty inline declarations -.-

Type constraints (at least non-interface ones) should be rather easy to do. The hardest part might be the parsing.

Regarding generic methods: I've already found the points where I'll need to hook in and keep those in mind while extending/adjusting the existing code, but that's it currently.

Regards,
Sven