FWIW, I'm inclined towards the variadic macro solution.

Maybe, as Albrecht suggested earlier, we can include something in the docs. to the effect of "If you are using an older compiler that does not support variadic macros, this feature will not be available, so in that case do not use it!"

I'd assume anyone choosing to use an old compiler toolchain is doing so for a reason, probably knows what they are doing, and may well be running on ancient hardware that has limited capabilities anyway...