On Wed, 21 Feb 2024 at 19:56, Thiago Macieira <thiago.macie...@intel.com> wrote: > > On Wednesday, 21 February 2024 09:19:19 PST Mathias Hasselmann via Development > wrote: > > How that? > > > > https://wiki.qt.io/Coding_Conventions#Things_to_avoid says: > > > > "Avoid the use of anonymous namespaces in favor of the static keyword if > > possible." > > Back in the day, this was a better suggestion. Now, it's equivalent so it's > distinction without a difference.
Not quite. I happened to be the evil NB representative who convinced WG21 to take a serious look at undoing the deprecation of static in namespace scope in favor of using unnamed namespaces, and this Core Issue elaborates why: https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_closed.html#174 To what extent the second bullet is relevant any more, I don't know. But for compatibility reasons, and not just for legacy compatibility reasons, the distinction isn't without a difference, because there is a difference in some code not being able to use unnamed namespaces. Now, having said that, that doesn't mean we couldn't recommend using unnamed namespaces instead of static in namespace scope, for our own new C++ code. We technically could, but as Andre says, there are plausible reasons why some programmers might just prefer using simple statics instead of wrapping in unnamed namespaces. In general, I would prefer style guides and design guides and programming guides to help programmers avoid mistakes, and to write good code. Using static in a namespace scope isn't a mistake, and it isn't bad code. It's a simple facility that various programmers easily understand, and use correctly. Are unnamed namespaces strictly better than using static in namespace scope? I don't think so. Are unnamed namespaces strictly worse than using static in namespace scope? I don't think so, either. What I do think is that the trade-offs of either of them aren't obviously applicable to every situation. And as Andre points out, there are trade-offs that aren't just differences in semantics. It sure looks like we should certainly make *some* change in those conventions, because the referred standardese, which is now [basic.link]/4, certainly doesn't give names declared in an unnamed namespace external linkage. -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
