“template polymorphism” when calling function for templated parameter of base type, with derived type?

Question

I\'ve got a template class:

template 
class TemplateClass
{
   //irrelevant what this class does
}

And two classes, one base

Answer 1

Sadly, C++ does not support template covariance, so you cannot do that automatically. As a workaround, you could do something like this:

template 
void DoSomething(const TemplateClass& tc) {
    // in C++03, use BOOST_STATIC_ASSERT and boost::is_convertible
    static_assert(
        std::is_convertible::value,
        "Template argument must be convertible to Base*"
    );

    // ...
}

Demo on ideone.