RE: breaking compatibility

[Benjamin Kosnik <bkoz at redhat dot com>]

aaaaagh. I don't know what to tell you. 

#include <iosfwd>

is clearly what should be done. I'm not sure why this doesn't work with 
both g++/libstdc++-v3 and VC++, but it should. That's one of the reasons 
so much work has gone into making a standards-conformant C++ library for GNU.

> The biggest concern here is that the project still has to build in Visual
> Studio (MS Visual C++) :( ... Visual still uses pretty separate *.h headers
> from the new extentionless headers... and they don't mix well... we have, in
> the past, tried switching to the new ISO extensionless headers, but we
> encountered some real problems... 

Have you tried switching over completely to the "extensionless headers" 
for both VC++ and g++? Maybe the tack you should take is to port the VC++ 
headers over to these headers, and then port this to gcc-3.

Doing this means you'll have to cope with namespace std:: issues, which 
you'll have to deal with sooner or later anyway. Herb Sutter wrote a good 
article in Dr. Dobbs (I think) recently about coping with the transition: 
you might want to check it out.

> Unfortuantely the Linux/gcc port is a
> splinter effort, and has to cow-tow to the will of the larger Windows/Visual
> C++ code-base... If you can think of a way to get this working with visual
> *AND* gcc without requiring us to change several thousand lines of code this
> would be best for us...

... I'm glad to help, but I think that in the long-term, going for 
standards conformance and the minimum number of gross hacks is the way to 
go. If you run into libstdc++-v3 specific problems, I'd be glad to help you.

best,
benjamin