Stringize __VA_ARGS__ (C++ variadic macros) - c++

Question

Let's have
class Item{
public:
Item(int id,const char *name,const char *props=NULL);
};
And I want to write:
ITEM(1,FIRST);
ITEM(2,SECOND, WithSomeProps);
With a macro
#define ITEM(ID,NAME,...) new Item(ID,NAME, #__VA_ARGS__ )
That #__VA_ARGS__ compiles well on gcc but gives an error on VStudio. Is there a solid and portable solution?
I want to have a collection of ITEM() in a .h file that will be included several times with different #definitions of ITEM.

Answer 1

GCC and Visual Studio handle Variadic Macros differently, because Macros are based on the compiler preprocessor (they are expanded at preprocessing time).
One of the difference is how they handle the empty variadic macros.
One of them will allow empty __VA_ARGS__ while the other will cause a compiler error if the __VA_ARGS__ is empty.
On your example the first the line ITEM(1,FIRST) will cause an error at compile time, while working ok on the other .
One workaround for this is to have an empty first argument, so your constructor will be something like :
Item(int id,const char *name,void *allwaysNull, const char *props=NULL);
And then have your Macro initialziations like this
ITEM(1,0,FIRST)
ITEM(2,0,SECOND,WithSomeProps)
What is weird is that from my experience it was GCC that was having problems with empty VA_ARGS for variadic macros...