using c++ for functions

Hello,

    I would like to know if it is possible to use C++ code
to define new functions in Postgres, something like :

    create function ... returns ... as '...' language 'c++';

It works very well for C functions, but with C++ (on unix/linux
systems), postgres
can't find the function in the symbol table.

Does anyone knows ?

Thanks,

David
dgross@lri.fr