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POInterface-like inheritance in C++
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copied!<p>I have the following situation, pictured is the theoretical inheritance graph of my classes:</p> <p><img src="https://i.stack.imgur.com/jT9rk.png" alt="Inheritance Graph"></p> <p>The idea is basically to</p> <p>1) have two abstract base classes that can be implemented on different platforms (in my case two different operating systems)</p> <p>2) allow BBase to be up-castable to ABase to be able to handle both equally at times (e.g. to hold instances of both types in one list).</p> <p>3) implement certain common functionality in ABase and BBase.</p> <p>Now, what would be the best way to represent this in C++? Even though it does support multiple inheritance, multi-level inheritence like this is not possible to my knowledge. The problem is that B inherits from A and BBase, which both in turn inherit from ABase. Simply translating this 1:1 (following code) in C++, a C++ compiler (GNU) will complain that ABase::foo() is not implemented in B.</p> <pre><code>class ABase { public: virtual void foo() = 0; void someImplementedMethod() {} }; class BBase : public ABase { public: virtual void bar() = 0; void someOtherImplementedMethod() {} }; class A : public ABase { public: A() {} void foo() {} }; class B : public A, public BBase { public: B() : A() {} void bar() {} }; int main() { B b; return 0; } </code></pre> <p>How would you change this inheritance model to make it compatible to C++?</p> <p><strong>EDIT:</strong> Inverted arrows in diagram and corrected "down-castable" to "up-castable".</p>

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