libstdc++-v3 + libstdc++ + libio + CVS gcc

[Martin v. Loewis]

> Here's a patch that implements this, using --enable-libstdcxx-v3 as
> a starting point.

Very good. Actually merging the CVS repositories is another challenge,
but I guess there are plenty CVS experts around.

> 	  Perhaps --enable flag should flip a switch and define this?
> 	  Could do something ugly and define
> 	  int flag_honor_std = _GPP_ENABLE_NAMESPACES;
>           Where this macro is determined at configure time, as
>           config.h is included in gcc/cp/decl2.c

Actually, this is what I had in mind. It is pretty much in line with
other default settings, such as

#ifndef DOLLARS_IN_IDENTIFIERS
#define DOLLARS_IN_IDENTIFIERS 1
#endif
int dollars_in_ident = DOLLARS_IN_IDENTIFIERS;

With that change, people don't have to pass -fhonor-std every time
they invoke a libstdc++-v3 based compiler. The default configuration
should just work, allowing

g++ hello.cc
./a.out

IOW, options that you must specify to get anything to work at all are
a bad thing, they really should be options.

Regards,
Martin