Re: [boost] Boost inspection notification (2006-09-28/RC_1_34_0) *X*

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2006-09-29 09:44:15

"David Abrahams" <dave_at_[hidden]> wrote

> Yeah, but be really careful, because there are only a few good ways
> to use an unnamed namespace in a header.  In fact, the only legitimate
> way to fix the Boost.Bind placeholder issue for header-only libs,
> without ODR or order-of-initialization issues, is:
>
>    // placeholders.hpp
>    template <class SomePOD>
>    static pod_singleton
>    {
>        const SomePOD instance;
>    };
>
>    template <class SomePOD>
>    SomePOD const pod_singleton::instance = { /*optional contents*/ };
>
>    namespace
>    {
>         some_pod const& _1 = pod_singleton<some_pod>::instance;
>    }
>
> That's an unnamed namespace in a header.

Why doesn't it have ODR issues?  Isn't it still possible to cause ODR 
violation by using _1 inside a class/template definition in a header?

Regards,
Arkadiy