But then you can't call those methods from C yourself (expecting va_list, received arguments). And what about adding methods to classes from plain C functions? Do you duplicate those functions with a va_list version? Seems like that'll add quite a bit of bloat.
I think the point was that you cannot implement this particular function in C - a function that forwards arguments to other functions, given a particular standard ABI. You've changed the requirements by saying that now the other functions use a different ABI, so you've missed the point of why it's impossible to implement this function, in these circumstances, in C.
The original question in this thread was whether it was really impossible, under any circumstances, to write this in C, as part of an Objective-C implementation that you fully control. It is possible in C, if you can control the ABI. It's the people who insist on a particular pre-existing ABI who are changing the question.
Anyway, I think I've said all I'm going to say here.
