Mechanism to mutate a C library to either static or dynamic

[markfinal]

I don't know if this is possible, given the current hierarchy in the C package, but if I want a library that can be either static or dynamic, currently, I have to rewrite two modules.
I'd rather write one, and choose at build time which one it is.

[markfinal]

Although I'm currently thinking about an abstract base class that covers all the common bits, and then two very small concrete Modules, one for static and one for dynamic.