c++ - How to force all derived classes to implement a virtual method? -

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Say that you have a base class Dep for a tree of orbits is a virtual method < Code> Dep * Dep :: create () is that I want to implement it by every single leaf class. Is there any way to implement it?

Note: The problem here is that to apply this method, make intermediate classes (such as class B: public A: public dep code> A :: Code>) or because they think are those leaf classes, but in fact they are sub-classified.

The question ends here.

Reference

If you are curious why do I need it; I have a class master in which the unknown concrete type of Dep objects are repeated if I master is repeated, then I Dep example mail clone. Even after this, I can not catch it (secondly by crashing so badly), because for unclear reasons, people who have more to say than me, in this project dynamic_cast has been declared unlawful (perhaps it There is a good decision, but still totally different discussions).

Curiously using recurring template fun, you can get something similar: 

  template & lt; Typename T & gt; Class Clonable: Public T, Public Department {Private: Clonable & lt; T & gt; (): T () {} Public: stable clonal & lt; T & gt; * Create () {New Clone Eligible & lt; T & gt; (); } Cloning & lt; T & gt; * Clone () {New Clonable Back & lt; T & gt; (* this); }}; Instead of using   
  deep  and using  new MyType  instead of  clonable . Since  is clonable & lt; MyType & gt; From  to  MyType , you can use the same way you would use the  MyType , except that it is currently in the  Depre :: Clone .  
 In addition, your  master  should not accept an example of type  Dep , but apply it to a  clonal & lt; T & gt; . (Change your function with a simple function template, which implements it.) It guarantees that any  Dep  inside the master is correctly implemented  clone  Function.  
 Since  can be cloned & lt; MyType & gt;  does not have any public constructor, it can not be inherited, although your actual  MyType  is more in heritage and can be used already.

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