Combine multiple classes

Is it possible to combine two (or more) class declarations into one?
This should be similar to multiple inheritance I guess, but should work with slots.

For example:

@define
class Point2d:
    x : int
    y : int

@define
class Line:
    start : Point2d
    end : Point2d
    
@define
class StrokeProperties:
     size : float
     color : Color
     
DrawnPoint = some_magic(Point2d, StrokeProperties)
DrawnLine = some_magic(Line, StrokeProperties)

print(DrawnPoint.x, DrawnPoint.size)

One could argue, that composition should be used instead, but I think it could be nicer to be able to access attributes without nesting.

Is there something like this in attrs, or how it could be done using existing api?

Start by reviewing attrs' existing class-composition and inheritance APIs, with particular attention to the slots requirement described in the issue. Determine whether the requested flattened attribute access is supported or needs a new design; done would be a documented existing approach or a clearly scoped feature proposal.