On Wed, Apr 26, 2023 at 11:21 PM Arthur O'Dwyer via Std-Proposals <std-proposals@lists.isocpp.org> wrote:
FWIW, I'm strongly opposed to this. (And I did a double-take at Barry's post: is it April Fool's Day already?)  C++ isn't Perl; we don't use Unix shell globs like that. In C++, curly braces have a couple of different meanings (code block, initializer-sequence), but not "shell glob."

Compare:

using A::{X,Y,Z};

and

enum A {X,Y,Z};

Notice, both are comma-separated brace-enclosed lists of names.  Also, in both cases, each name is introduced into its parent scope.

A slight alteration we could consider would be:

using A {X,Y,Z};

(drop the extra ::), and then perhaps that seems more natural?

It's a common coding style to have a big block of usings at the top of a .cpp file.  This feature would significantly shorten that block.