On 2015-03-12 01:05:42 +0000, Joseph Myers wrote:
> On Wed, 11 Mar 2015, Vincent Lefevre wrote:
>
> > BTW, the following is forbidden (and makes no sense), but is accepted
> > by GCC without a warning:
> >
> > int foo (void)
> > {
> > union { char a[8]; int b; } u = { .a = { 0 }, .b = 1 };
> > return u.b;
> > }
>
> What constraint do you think forbids it? It looks like an ordinary case
> of overriding with designated initializers.
It seems that the standard doesn't specify the behavior.
Concerning the override, I could only see 6.7.9p19, which says:
The initialization shall occur in initializer list order, each
initializer provided for a particular subobject overriding any
previously listed initializer for the same subobject;151)
but in the case of a union, .a and .b are not the same subobject
since they don't have the same type (and not necessarily the same
size).
--
Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
