Can a class member function template be virtual?

Question

I have heard that C++ class member function templates can\'t be virtual. Is this true?

If they can be virtual, what is an example of a scenario in which one would

Answer 1

While an older question that has been answered by many I believe a succinct method, not so different from the others posted, is to use a minor macro to help ease the duplication of class declarations.

// abstract.h

// Simply define the types that each concrete class will use
#define IMPL_RENDER() \
    void render(int a, char *b) override { render_internal(a, b); }   \
    void render(int a, short *b) override { render_internal(a, b); } \
    // ...

class Renderable
{
public:
    // Then, once for each on the abstract
    virtual void render(int a, char *a) = 0;
    virtual void render(int a, short *b) = 0;
    // ...
};

So now, to implement our subclass:

class Box : public Renderable
{
public:
    IMPL_RENDER() // Builds the functions we want

private:
    template
    void render_internal(int a, T *b); // One spot for our logic
};

The benefit here is that, when adding a newly supported type, it can all be done from the abstract header and forego possibly rectifying it in multiple source/header files.