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c++ - Can I get polymorphic behavior without using virtual functions?

Because of my device I can't use virtual functions. Suppose I have:

class Base
{
    void doSomething() { }
};

class Derived : public Base
{
    void doSomething() { }
};

// in any place
{
    Base *obj = new Derived;
    obj->doSomething();
}

the obj->doSomething() will call just the Base::doSomething()

Is there a way with Base *obj, to call the doSomething of the Derived?

I know I can just put a virtual before doSomething() of Base it solve the problem, but I'm limited by my device, the compiler doesn't support it.

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1 Answer

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by (71.8m points)

You could down cast the base class pointer to the derived class and call the function.

Base* obj = new Derived;
Derived* d = static_cast<Derived*>( obj ); 
d->doSomething();

Since doSomething() is not declared virtual, you should get the derived implementation.


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