On Sun, Apr 30, 2023 at 7:54 PM Gavin Lambert via Boost < boost@lists.boost.org> wrote:

A Boost implementation *must not* provide a definition appearing in the std:: namespace. (Except where expressly permitted by std extension points, such as std::hash. Though those make me sad.)

Nobody is talking about putting anything inside namespace std. We're talking about writing equivalents of std in namespace boost. Glen