[boost] GPL and boost

Subject: [boost] GPL and boost
From: Stefan Strasser (strasser_at_[hidden])
Date: 2009-12-28 08:06:17

Hi,

is there a precedent of optional(!) external library dependencies to GPLed 
libraries in boost?
IIUC the implementation of the interface to the library in boost would 
constitute a derivative work of the GPLed library and therefore be "infected" 
by it.
do the terms of the GPL then only apply if a boost user is actually using this 
optional code and linking to the external library or does this inhibit the 
distribution of such code with boost releases in general?
and if so, is external distribution, e.g. in the vault, but documentation in 
the main library acceptable?

I'm asking because of a possible interface to Oracle's Berkeley DB, but I 
guess this will come up again with Boost.Rdb and GPLed SQL databases.