Is it possible to setup a dimension that is both driven and drives another dimension?

Essentially it would be nice if solidworks could solve the equation when a driven dimension is "set".

e.g., suppose we have a rectangle with the width = 2.354*length. It would be nice if we could EITHER set the width or the length rather than ONLY the length. It shouldn't be difficult(at least for simple equations) for solidworks to solve the equation for length = 1/2.354*width.

In my case I am working with a hollow cylinder. I would like to be able to dimension both the radii and the thickness. Sometimes I might want to set the thickness and sometimes I might want to set the radius. In any case there is a direct relationship where thickness = outer radius - inner radius. If I use a driven dimension then I am limited to only setting one(in which case it is somewhat useless to even have a thickness dimension in this case).

Another very simple example is setting either the radius or diameter of a circle. If you drive one with the other then it is useless to have 2 since only one can be changed. It would be nice for SW to allow either one to change but keep the consistency.

I doubt SW handles this but maybe there are some tricks.

I wouldn't mind setting 2 equations up so that if one sets one dimension it will drive the other and vice versa.