[Cycles] 3d Anaglyph Output

Without using the compositor to separate/combine RGB …

Is there a way to render an animation and output (to file) the 3d anaglyph, plus the L + R as separate files?

I’m talking about the built-in ‘stero 3d’ option in the render layers settings.

I know how to do it manually by having two cameras, duplicate the scene, seprate then combine the RGB … have output nodes for each view … but … I want to make this more automatic and use the existing function as mentioned above.