Inversed --use option variant

[nick87720z]

There could be option like --no-use, which would have inversed effect comparing to --use, i.e. select packages, that don't have mentioned flag.

As for use case (I just have it), it could be used with --installed-with-use to find installed packages that dropped some obsoleted use flag. E.g. I could use it to find those, which droped python2_7 support. For now I had to do it with diff:

diff \
<( eix -c --installed-with-use python_targets_python2_7 --only-names ) \
<( eix -c --installed-with-use python_targets_python2_7 --use python_targets_python2_7 --only-names ) | less

but that's not as convenient as if packages were listed by eix.

[vaeth]

You can use logical expressions everywhere in your query. I suppose that

eix -c --installed-with-use python_targets_python2_7 --and --not --use python_targets_python2_7

will do what you want.