How to determine if a surface is a simple or compound surface.

I have a composite part with some curved surfaces that have a foam core.

I would like to double check that they are simple curves (they are generated via the loft function) and that the foam can be bent into these curves. Obviously if they are complex/compound this will not be possible.

I am aware that the curvature tool will display this but i would really like to find a method that will provide an objective answer.

Thanks in advance.

SolidworksSurfacing