Design problem with a virtual template class

[Paul McKenzie]

I use GCC on Linux.

What version of GCC? That compiler has gone through many revisions, so you need to specify exactly which version of the compiler you're using.

Anyway Comeau, as I've read, is a good compiler. It even support the export keyword. But this is not standard code,

The export keyword is standard -- the issue is that very few compilers support it right now.

Regards,

Paul McKenzie