state of libstdcxx_so_7-branch

[Benjamin Kosnik]

> Humm... In practice, if I remember correctly, we could do the same we 
> did between gcc2.95.3 and gcc3.0.0: for some time we had two completely 
> separate directories, libstdc++ and libstdc++-v3. In that case, however, 
> we never shipped libstdc++ together with the new gcc3.x series, we 
> renounced to a compatibility mode. In this case we could start the same 
> and then we'll see...  

Yes.

> Also, in the present case the libstdc++-v3 
> directory would stay in sync with the mainline one, thus including some 
> C++0x non-ABI breaking features, ported from libstdc++-v4.

I'm thinking that libstdc++-v4 has to be added at the same directory 
level as libstdc++-v3 in the gcc subversion directory for this to 
actually work though.

Although we are talking about managing divergence mostly from the source 
perspective, I think this may give us more flexibility for finding 
compatible binary solutions, in that iff C++0x had unique symbols from 
C++98, conceivably a mode could exist where .so.6 contains the 
additional C++0x symbols. (Ie, both are built and then so.6 is augmented.)

Hmmm.

-benjamin