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My compiler says that a member of a base class template is not defined in a derived class template. Why is it not inherited?

April 26, 2017base class compiler defined derived inherited Template

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My compiler says that a member of a base class template is not defined in a derived class template. Why is it not inherited?

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template class base { public: void base_func(); }; template class derived : public base { public: void derived_func() { base_func(); // error: base_func not defined } }; A: It is inherited. However, the standard says that unqualified names in a template are generally non-dependent and must be looked up when the template is defined. Since the definition of a dependent base class is not known at that time (there may be specialisations of the base class template that have not yet been seen), unqualified names are never resolved to members of the dependent base class. Where names in the template are supposed to refer to base class members or to indirect base classes, they can either be made dependent by qualifying them or brought into the template’s scope with a using-declaration. In the example, this could be achieved by replacing the call to base_func() with this->base_func() or base::base_func(), or by adding the declaration using base::base_func;.