On Sep 29, 2011, at 5:54 PM, Basile Starynkevitch wrote: > On Thu, 29 Sep 2011 17:10:26 +0200 > Tristan Gingold <ging...@adacore.com> wrote: > >> Hi, >> >> DEC-C, the DEC compiler provided on VMS, has added to ANSI-C at least one >> extension that is difficult to work-around as it is used in the system >> headers: varargs without named argument. It makes sense on VMS because of >> its ABI which pass the number of arguments used. >> > > I believe that such an extension is useful on other systems, even when their > ABI don't > pass the number of arguments. > > The use case I would have in mind is when the signature of the called > function (that is > the number & types of arguments) is determined by something else, perhaps a > global > variable or data. Think e.g. of a printf-like function, except that the > format string is > conventionally assigned to some fixed global before calling it.
In fact you can't access to the arguments with ANSI-C as va_start needs a named argument. So you can't write such code. Tristan.
