is there a way to write macros with a variable argument list in visual C++?

Question

As far as I know, in gcc you can write something like:

#define DBGPRINT(fmt...) printf(fmt);

Is there a way to do that in VC++?

Answer 1

Yes but only since VC++ 2005. The syntax for your example would be:

#define DBGPRINT(fmt, ...) printf(fmt, __VA_ARGS__)

A full reference is here.

Answer 2

Yes, you can do this in Visual Studio C++ in versions 2005 and beyond (not sure about VS 2003). Take a look at VA_ARGS. You can basically do something like this:

#define DBGPRINTF(fmt, ...)  printf(fmt, __VA_ARGS__)

and the variable arguments to the macro will get passed to the function provided as '...' args, where you can then us va_args to parse them out.

There can be weird behavior with VA_ARGS and the use of macros. Because VA_ARGS is variable, that means that there can be 0 arguments. That might leave you with trailing commas where you didn't intend.