[madawan]

The way I work is, I make an interface{} red-black-tree, and then when I need to store things in it I create functions around it.

Suppose I'm storing Tiles in a Level: the Level struct will contain a (private) RedBlackTree and I'll define GetTile(Pos) Tile and PutTile(Pos, Tile) on Level which do the casting to and from interface{}.

I still have type safety since I cannot put/get anything but Tiles in the RedBlackTree. But I didn't need generics.

[microtonal]

From your description, it is not completely clear what you are ordering on, but typically in an RB tree you (at the very least) want to require some interface/function that specifies ordering and equality.

Of course, in some cases you can do casting on your interface boundaries. But in many other cases this is not possible, e.g. if you want the API to return an ordered set or map.

[fauigerzigerk]

You can only do that in places where you don't care about memory usage at all.