c++ - How can I avoid the Diamond of Death when using multiple inheritance? -

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http://en.wikipedia.org/wiki/diamond_problem

i know means, steps can take avoid it?

a practical example:

class {}; class b : public {}; class c : public {}; class d : public b, public c {};

notice how class d inherits both b & c. both b & c inherit a. result in 2 copies of class being included in vtable.

to solve this, need virtual inheritance. it's class needs virtually inherited. so, fix issue:

class {}; class b : virtual public {}; class c : virtual public {}; class d : public b, public c {};

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