libpqxx : C++ client API for PostgreSQL. The standard front-end for writing C++ programs that use PostgreSQL. Supersedes older libpq++ interface. ( http://thaiopensource.org/development/libpqxx/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a postgresql-experimental
For Paludis use this rsync : rsync://gentoo.zugaina.org/postgresql-experimental-portage
If you have a problem : ycarus(-at-)zugaina.org