bogus restriction

From: David Abrahams (dave_at_[hidden])
Date: 2005-02-09 11:23:23

The extender manual says:

If the tool's version can be specified during initialization, make
sure the version is either always specified, or never specified (in
which case the tool is initialied only once). For example, if you
allow:

using yfc ;
using yfc : 3.3 ;
using yfc : 3.4 ;

Then it's not clear if the first initialization corresponds to
version 3.3 of the tool, version 3.4 of the tool, or some other
version. This can lead to building twice with the same version.

In my opinion that would not be so terrible, and would be much less harmful
than this restriction is. Currently if I'm a site administrator I
can't write

using gcc ;

for my average user if I think some advanced user may need

using gcc : 3.3 ;

in his site-config.

Much better would be to allow the versionless toolset to exist
alongside the versioned one (possibly issuing a warning), and --maybe-- either:

1. provide a way for users to un-configure the versionless toolset

or

2. have the toolset automatically un-configure a versionless toolset
if the user ever specifies a version number.

I favor #1.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com