> > No, you can't cast a union or structure, but you can cast a pointer to
one.
>
> Interesting. gcc *will*  cast a union as long as one of the elements in
> the union is of the same type of the object being cast.
>
> E.g.:
>
> union i_c {
>   int i;
>   char c;
> };
>
> ...
>
>  unsigned int ui;
>  int i;
>  char c;
>
> ...
>
>   c = ((union i_c)i).c;    // not an error
>   c = ((union i_c)ui).c;   // error
>


hmm...

Definitely not ANSI standard behavior (but that is no surprise with GCC
which contains many 'extensions' to the standard).

I'd like to look at the generated code. I wonder if it is actually doing
something like:

union_i_c temp;
temp.i = i;
c = temp.c

Also, can you use this as an LValue?:

((union i_c i).c = 'X';

Bob Ammerman
RAm Systems

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