[PATCH] c++, libstdc++, v3: Implement C++26 P3726R2 - Adjustments to Union Lifetime Rules [PR125845]

[Jakub Jelinek]

On Wed, Sep 09, 2026 at 12:06:14PM +0200, Tomasz Kaminski wrote:
> > +      __builtin_start_lifetime (&b.b);
> > +      __builtin_start_lifetime (&b.b[1]);
> > +      __builtin_start_lifetime (&b.b[1].b);
> > +      __builtin_start_lifetime (&b.b[1].b[0][1]); // { dg-error
> > "'__builtin_is_within_lifetime' with containing object not within lifetime"
> > }
> >
> Should the error say,  __builtin_start_lifetime with containing object not
> withing lifetime?

Sure, I can pass const char *name too.

	Jakub