I'm implementing an application with different code paths that shall be chosen once at startup and then fixed forevermore for that execution- for example, choosing D3D11 or D3D9 rendering path. Obviously I don't want to duplicate all my other code. Is run-time inheritance (no virtual inheritance) a fair solution? I don't want to waste a bunch of performance making virtual lookups when the type was fixed long ago. Not just that, but it makes me nervous that the functions can't be inlined and whether or not it affects RVO and NRVO and such. Am I just being over-concerned about this?