Re: multivalued feature (was Re: [jamboost] Re: [BBv2] quickbook.jam and boostbook question)

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-02-03 09:38:06

On Thursday 03 February 2005 15:51, Zbynek Winkler wrote:
> Vladimir Prus wrote:
> >>I tried to use feature.set-default but I got an error stating
> >>/path/to/quickbook is not an allowed value...
> >
> >Unfortunately, "free" features can't have default value, because "free"
> >features non only can have any value, but can be specified several times.
> > So it's unclear when we should add default value -- when none is
> > specified, or always?
> >
> >I hope to fix this one day, by separating "free" features from
> > "multivalued":
> >
> > http://zigzag.cs.msu.su:7814/scarab/issues/id/BB79
>
> What is (will be) the semantics of multivalued features? I've read the
> issue but it seems that it is just asking to be able to set default
> value to a free feature and be able to override that from the command
> line if necessary.

Right. The idea is that for free but non-multivalued feature, you'll be able 
to specify default and override it on the command line. It will be just like 
current <optimization>, except that the list of value is not fixed.

Free multivalued features will behave like current free -- no default allowed, 
and specifying a value anywhere will add another value to existing values (if 
any).

- Volodya