For me, it was just to have some fun seeing whether you can get the convenience of generics in C without blowing up the size of a "minimal standards-compliant compiler." E.g., Chibicc[1] is only a few thousand lines of code; adding Gamma to that would not blow it up by much. There's something aesthetically pleasing about knowing I can read the whole thing in a few days. Nothing like that is possible for C++ (or D?) AFAIK.
But yes --- for a real project I would absolutely recommend someone use D over this !
Totally fair. Just wondering if there was some specific motivation for being able to do this... "For fun" is valid, IMO. ;-)
Therefore it's very jarring with this text after the first C code example:
This uses a static variable to have it persist between both the compare function calls that qsort makes and the main call which (potentially) changes its value to be 1 instead of 0
This feels completely made up, and/or some confusion about things that I would expect an author of a piece like this to really know.
In reality, in this usage (at the global outermost scope level) `static` has nothing to do with persistence. All it does is make the variable "private" to the translation unit (C parliance, read as "C source code file"). The value will "persist" since the global outermost scope can't go out of scope while the program is running.
It's different when used inside a function, then it makes the value persist between invocations, in practice typically by moving the variable from the stack to the "global data" which is generally heap-allocated as the program loads. Note that C does not mention the existence of a stack for local variables, but of course that is the typical implementation on modern systems.