[gentoo-dev] [RFC] [EAPI=3] Add approprietly prefixed values of IUSE_* variables to IUSE

[Arfrever Frehtes Taifersar Arahesis]

I would like to suggest that values of IUSE_* variables (whose names end with
values of USE_EXPAND variable), after prefixing with lower-cased names of
appropriate variables included in USE_EXPAND, should be automatically added
to IUSE variable.

Example:
IUSE="abc"
IUSE_LINGUAS="en fr +la pl ru"

Effective IUSE would be "abc linguas_en linguas_fr +linguas_la linguas_pl linguas_ru".

Currently ebuilds need to manually add such flags to IUSE.

It's a zero-cost feature implemented in the attached patch, so including it
in EAPI=3 (after temporary unlocking of list of features of EAPI=3) wouldn't
delay implementing support for EAPI=3 in Portage.

-- 
Arfrever Frehtes Taifersar Arahesis