Couldn't get so far with this one. It seems that the only way to nest macro loops in loops is to generate more loops... secondary loops. I read some stack overflow posts and yes, they're using a technique where they combine #ifdef and macros in some kind of woah way (I'd called ugly cause it's probably ugly to read, but since they can do more with that than me - I can't say anything!). So they can generate more and more macros with this trick and get their more more versatile thing done. I don't like to admit that, but I may consider taking a different look at it. It's so much work, not rarely extreme amounts of work I see right there from source to license. I still don't like it all, it's too much stuff I disagree with. Too many too complicated template constructs the compiler needs to instanciate and evaluate. I mean take a look at all these functionalities etc and say why this doesn't like somebody wanting to just integrate a special syntax for something you can also get otherwise... It seems forced, out of "we can do it" and completely off reliability. Reliability in a sense that you can't rely on it beeing simple enough to ever work as minimal as it could. I don't know. I still dislike it.
And that's also the end for today and probably for macro programming, too. I have better things to do.