Re: sizeof a union

Jordan Abel wrote:
On 2005-11-29, pemo <usenetmeister@xxxxxxxxx> wrote:
"Mockey Chen" <mockey.chen@xxxxxxxxxx> wrote in message news:dmhr15$9l8$1@xxxxxxxxxxxxxxxxx 
My friend ask me a question as following:

give a union SU define as:
typedef union _SU
{
short x;
struct y{
 char a;
 short b;
 char c;
};
}SU;

what is the sizeof (SU)?

My compiler tell me the answer is 6.
I want to know why the answer is 6.

Why not add another member and use that to 'explore' the other members, e.g.,: 

[snipped]

Out of curiosity, why is it impossible to add a 'flexible array' to a
union? The best solution to this IMO would be an "unsigned char data[];"
member.

Because that's pointless. If you want that, cast the address of the thing to an unsigned char* and use that. Overloading flexible arrays for that isn't worth it.

S.
.

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