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From: David Abrahams (dave_at_[hidden])
Date: 2007-03-15 14:18:16

[How did this message end up on the boost developers' list? I set the
followup-to header so that it would go to boost-build, *and* I
explicitly asked for followups to go there at the top of my previous

on Wed Feb 21 2007, Vladimir Prus <> wrote:

> David Abrahams wrote:
>> * If we drop the ability to arbitrarily choose a version string, we
>> need a way to identify different configurations of a toolset that
>> may have the same version number. For example:
>> - You may have both Cygwin and MinGW gcc 3.4 installed
>> - You may want to experiment with a special gcc build having C++0x
>> features
>> - You may need a convenient way to identify a special configuration
>> of an existing toolset.
>> The solution we came up with is to add an optional argument to
>> "using" that allows you to create a special toolset subfeature
>> on-the-fly, something like:
>> using gcc : 3.4 : /usr/local/conceptgcc/bin/g++ : conceptgcc ;
>> This feature could then also be used to identify the toolset on the
>> command-line, something like:
>> bjam toolset=conceptgcc
> I'm actually not sure if using "toolset=XXX" like this to alias
> to some other set of properties is good idea -- we might end up
> with lots of corner cases.

What kind of corner cases?

> I'd much rather have some "user-defined" subfeature,

Yeah, that's exactly what

       using gcc : 3.4 : /usr/local/conceptgcc/bin/g++ : conceptgcc ;

is supposed to create. Or at least, a value of an implicit
user-defined subfeature, e.g. <flavor>conceptgcc

> and then use:
> gcc-3.4-conceptgcc,


> or maybe
> gcc-3.4 flavour=conceptgcc

I don't like that one, because, for example, you might want to build
with plain gcc-3.4 as well as the conceptgcc flavor.

> or maybe
> gcc-3.4 <some-better-feature-name>=conceptgcc

The US English spelling of flavor is shorter.


Just kidding; I think "flavor" is fine.

Dave Abrahams
Boost Consulting

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