Re: [Boost-build] ** Need input on alternative selection **

From: Johan Nilsson (r.johan.nilsson_at_[hidden])
Date: 2007-04-20 02:15:30

Vladimir Prus wrote:
> On Tuesday 17 April 2007 13:55, David Abrahams wrote:
>

[snip]

>> My definition of "best" is not arbitrary; there's a sensible
>> rationale for valuing properties that are explicitly specified over
>> those that arise implicitly.
>
> Which rationale is that? I personally thing that there should be
> no difference between specifying a default value of some feature
> on the command line and not specifying it at all. If
>
> bjam
>
> and
>
> bjam toolset=gcc variant=debug threading=single
>
> starts to be behave differenly, it's gonna be rather confusing.

I'd have to disagree with this. If you simply run "bjam", you presumably
mean that "I don't really care about what features are used, as long as it
compiles".

On the other hand, if you run "bjam feat1=val1 feat2=val2" you presumably
mean that "I don't really care about most of the different features, but
having these two features set to these specific values are important
for me (to some degree).

If the values I specify happen to be the same as the default ones really
shouldn't make any difference to the above.

>And
> note
> that user might write
>
> bjam variant=debug,release
>
> to build both debug and release variant. Should the debug build be
> different from one from
>
> bjam

In terms of target selection, yes. You're putting an emphasis on that you
want to build both debug and release variants, as opposed to relying on
defaults.

/ Johan