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Template and inheritance

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jihane jihane -  
Hello,

Please, can a derived class use the generic type of the base class if the base class is declared as a template
template<class T> NAME OF THE CLASS? In other words, can we use the keyword T instead of the type in the derived class? Thank you for your forthcoming reply :)

1 answer

  1.  KX Moderator
    Every time you replace your template with a concrete type, you compile a new class, which in turn will compile its parent class. In the end, you will only have concrete types. So there shouldn't be any problem... 

    template <typename T> class Parent { } template <typename T> class Child : public Parent<T> { }

    --
    Trust does not exclude control.
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    1. jihane jihane Author
      So we can say that the child class inherits the abstract type??? And thank you for the answer.
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    2. KX Moderator
      It is only abstract in your code; once the compilation is done, the class is concrete, and there is no more ambiguity than if you had created multiple parent classes and multiple child classes with only the template type differing.
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    3. jihane jihane Author
      OK thanks, but if I want to declare the child class as being generic but with a different type, that is to say not the one from the parent class, what would I do??
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    4. KX Moderator
      You would act as if the parent class was not a template...

      I am not sure about the syntax with two templates, but in principle, these two codes should have roughly the same meaning for the child class. 

      class Parent {} template <typename T> class Child : public Parent {} //------------ template <typename U> class Parent {} template <typename T,typename U> class Child : public Parent<U> {}
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    5. jihane jihane Author
      Thank you very much for helping me, and thank you for your time now I understand well :)
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