Where is the Weight Paint Brush Selector API?

Not implemented yet?
also there is only one brush in texture paint.
I wanted to assign a shortcut key, but Brush.active_index_set which was usable in 2.7 seems to be removed.
Is there a list of what has not yet been implemented in 2.8 and what has been implemented?

No one knows? Hmm.

Yes. Brushes have been categorized by their tool.
So, currently, shortcut does not call a brush anymore but a tool category of brushes.
For example if you create several clay brushes in sculpt mode and then, press C : it is latest used Clay brush that shows up and then, you have to continue to press C to cycle through other Clay Brushes.
But there is no way to assign a specific shortcut to a custom brush and directly call one that was not the latest used.

Sorry, I don’t remember the thread on devtalk forum but I remember that when I mentioned that : William agreed that a solution should be added for that.

Thank you. Does that mean it will not be implemented anymore? Or the answer is 2.8 Blender is still beta. That’s fine but.
Why was the developer lost it, although it was an excellent method of brush selection in 2.79?

I think they tried to limit number of loaded brushes directly accessible to solve a performance issue.
They did that by introducing categorization by tool and they adapted shortcuts to this new UI.
I don’t know if they thought that users will be satisfied as is or if they planned to restored the direct access to a custom brush in a better way later.

That’s very disappointing. thanks.