On Fri, 20 Jul 2012 14:37:19 -0400
Alexandre Rostovtsev <tetromino@gentoo.org> wrote:
> That suggests that the EAPI ought to define a second category of
> USE_EXPAND flags, one that has a different treatment of (+)/(-).
> 
> Something like the following:
> 
> A dependency on $foo[linguas_bar(+)] would be considered satisfied by
> an ebuild X matching $foo iff:
> 1. X has linguas_bar in IUSE and enabled; or
> 2. X does not have linguas_bar in IUSE, but there exists an ebuild Y
> (which may or may not equal X) matching $foo such that Y has at least
> one linguas_* flag in IUSE.

That's sensitive to old versions ebuilds being removed from the tree, so
it's utterly unworkable.

-- 
Ciaran McCreesh