Sorry, my example was not clear enough. The issue with using namespace + unifoed builds is that the using namespace declaration applies to all (or most) of the headers included in the unified translation unit. So using namespace mozilla at the top of each .cpp is harmless until we include third party libraries, which we do.
This build failure is a conflict between our gfx:: classes and some defined by 3rd party libraries we use on Mac. This is really not a style problem. It breaks builds. Cheers, Nical On Wed, May 21, 2014 at 4:36 AM, Ehsan Akhgari <ehsan.akhg...@gmail.com>wrote: > On 2014-05-20, 10:00 PM, Joshua Cranmer 🐧 wrote: > >> On 5/20/2014 8:37 PM, Ehsan Akhgari wrote: >> >>> FWIW, I argued against nested namespaces a few years ago (couldn't >>> find a link to it through Google unfortunately) and people let me >>> "win" that battle by allowing me to edit the coding style to prohibit >>> nested namespoaces in most cases >>> <https://developer.mozilla.org/en-US/docs/Mozilla/ >>> Developer_guide/Coding_Style#Namespaces>, >>> but unfortunately we never adhered to this rule in practice, and these >>> days three level nested namespaces are pretty common in the code base. >>> We're just bending C++ in a way that it's not quite comfortable with >>> here. >>> >> >> How about adding the rule "all new namespaces must be approved by >> <insert specific top-level superreviewer here>", just like all new >> top-level directories need to be explicitly approved? If we could get >> reviewers to enforce that, it would hopefully cut down on people using >> outlandishly long namespaces. >> > > I don't think that will work. IIRC I approached some module owners about > this back in the day and they explicitly told me that they don't care and > asked me to fix the rest of the places where we use nested namespaces, and > I ended up giving up on the whole idea. > > > I think there are valid reasons to have a two-level namespace (e.g., >> mozilla::mailnews [1]), but I find it deathly hard to justify going any >> deeper. >> >> [1] Actually, I would probably prefer mozilla::comm had >> mozilla::mailnews not already had precedent when I started using C++ >> namespaces. :-) >> > > See, this is the problem! Everyone thinks that it's reasonable to add > their own nested namespaces, and they're right as long as they don't look > at the big picture. As long as we allow any code to #include any other > code, this is a slippery slope. > > Honestly, speaking as the person who did the majority of the work to give > us unified builds, and presumably dealt with the most of this issue while > doing so, this is not a very important problem, and it's uncommon enough > that I don't think it warrants an effort to get a handle on our namespace > usage or add stricter review requirements. > > Cheers, > Ehsan > > > _______________________________________________ > dev-platform mailing list > dev-platform@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
