[gentoo-dev] Re: RFC: c++14 global USE flag

[Duncan]

Maxim Koltsov posted on Sun, 03 May 2015 13:19:18 +0300 as excerpted:

> this functionality can't be generalized by any name, except "c++14" ---
> that's only thing in common. Moreover, this is (I hope) a _temporal_
> solution, until there's a gcc with needed level of support. And of
> course we can put a message about this flag in eclass and/or on
> LeechCraft site.

What about a somewhat more generic flag such as newcode?  Like the bindist 
or minimal flags, this could be global, but with local descriptions very 
strongly recommended.  Similarly, like minimal, setting it globally would 
be strongly discouraged.

In this case, the newcode local description would be something like:

C++14 related: gcc doesn't support yet, requires clang

... with an appropriate use-conditional dep.

The newcode flag would however be generic enough that it could be reused 
for C++17, etc, as well, and could obviously be phased out for any 
particular package once its specific newcode dependencies are met in 
stable -- in this case, when a supporting gcc stabilizes.

newcode would even be generic enough to be used for say qt6 when the time 
comes, if it turns out to be stuck in the qt overlay for quite some time, 
as was qt5, for the longest time, and the good bit is, generic meaning, 
that USE=newcode requires a dep that's still generally problematic or 
might be considered excessive to get, for optional functionality that may 
or may not be considered worth it, should be pretty obvious.

Making that meaning even more obvious would be the fact that the flag 
would likely be packageuse-masked for many users for much of the the 
time.  That could for instance allow packages using it in-tree, before 
the dep it pulls in is itself in-tree, while still making it possible to 
unmask, for users who either already have the required overlay active, or 
who don't have it active ATM, but are willing to activate it to get the 
features it toggles.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman