Re: [Boost-users] variant: bounded types derive from same base class

My restriction is that f takes a ABC const-ref as an input. Can I construct the variant from the    const ABC& abc Maybe like    variant v(abc);

without deep copying. The Di objects are big.

Then I would apply the visitation.

Maybe storing variant...

Yes, you can store ptrs in the variant.

So f would look like

void f( const ABC& abc ) {   const VariantTypeDefProvidedByLib v(&abc);

   v.apply_visitor( YourVisitor ); }

You cannot construct the variant in f(), because you already lost the compile-time type of the object - it's ABC now. If you'd like to work with ABC's and virtual functions, then why do you need variant? Variant is about preserving the compile-time type.