Does gcc accept unions?

[Hihn Jason]

I have the following simple union:

typedef union 
{
 int    i;      // integer
 char  *str;    // string
 void  *p;      // pointer to whatever
 float *pf;     // pointer to a  float
 int   *pi;     // pointer to an integer
} ARG;

which looks legal to me (and other compilers compile it)
but I get on the "} ARG;" line:
parse error before `}' 
warning: data definition has no type or storage class

I've tried -traditional and -ansi, along with combinations of union ARG
{..};

Can anyone help me sort this out?
Thanks,
Jason