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Subject: [Bug c++/41874] Incorrect "dereferencing type-punned pointer will break strict-aliasing rules" warning
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------- Comment #2 from rguenther at suse dot de  2009-11-06 09:16 -------
Subject: Re:  Incorrect "dereferencing type-punned pointer
 will break strict-aliasing rules" warning

On Fri, 6 Nov 2009, pinskia at gcc dot gnu dot org wrote:

> ------- Comment #1 from pinskia at gcc dot gnu dot org  2009-11-06 09:09 -------
> 4.5 also fails and I cannot figure why if I do:

"fails"?

> #include <new>
> struct APInt {
>     int i;
> };
> int main() {
>     APInt I;
>     void *d;
>     char Data[sizeof(APInt)];
>     new((void*)Data)APInt();
>     d = Data;
>     *(APInt*)d = I;
> }
> 
> GCC does not warn.

Of course not - the code is perfectly valid (apart from Data
not having suitable alignment for APInt, but that's unrelated
to aliasing issues).

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41874