The index switch node already exists as a geometry node. This node allows user to switch between different inputs based on a given integer index.

However, this node does not exist as a shader and compositor node. I think it would be great to have it in both places as well, because another similar node, "Menu switch", exists as all types of nodes (compositor, shader, and geometry).

Example Use Case

Personally, I make use of shader switcher nodes extensively in my character designs that utilize 2D textures for animation (e.g 2D face textures in 3D model).

I've developed an add-on called Beantextures that generates such nodes. However, this add-on relies on stacking together several mix nodes. I think it's better to have a low-level implementation of switch nodes instead of hacking nodes together like this: