On 11/12/2010 02:55 PM, Francis Moreau wrote:
> "Segher Boessenkool" <segher@xxxxxxxxxxxxxxxxxxx> writes:
>
> [...]
>
>>>
>>> Looking again at the second example:
>>>
>>> int f() {
>>> union a_union t;
>>> int* ip;
>>> t.d = 3.0;
>>> ip = &t.i;
>>> return *ip;
>>> }
>>>
>>> could you tell me what the effective type of 't.i' object ?
>>
>> int, if you can say that object exists at all: it does not have a stored
>> value. The stored value of t is a double with value 3.0 . You can
>> take its address and access it via that as "double" (or "char"), or you
>> can access it as the union it is. You can not access it as "int".
>>
>
> BTW, does your reasoning rely on the C standard ?
It's a gcc extension. 5.25, Cast to a Union Type
Andrew.
