Ok I get it. I'm not sure that is the right way forward. The same
problem arrise for devirtualization and the solution does not
cover it. That is a problem.
First I'd like to have more compiler checks on template bodies.
Andrei and Walter are not super happy with it, but deep down I do
think their point is more the result of the clash with the C++
community over static if vs concept than based on any technical
merit (the whole thing is a false dichotomy to start with so the
clash and its results are nonsensical).
Second, it is most likely a good idea to issue some kind of error
when export within template code calls non export code. That most
likely needs to be an error. The error would show up with descent
test coverage even without the special feature.
