undefined reference to, but it is defined

I have a class A with virtual inline getters and setters. From A there are two classes B and C derived. And I have a class D, derived from B and C. Creatung an object from D and using the getName() results in "undefined reference to getName()". Removing "inline" doens't work. The header file is included correctly. What's the problem here?

class A
{
    public:
        virtual inline std::string getName() const{return开发者_StackOverflow中文版 name;}

    protected:
        std::string name;
};

class B : public virtual A {};
class C : public virtual A {};

class D : public B, public C {};

Your code compiles fine with/without inline : with inline and without inline

But remember this otherwise : in a virtual inheritance, you've to initialize the base explicitly IF the base class constructor takes parameter as,

class D : public B, public C 
{
   public:
      D(string s) : A(s), B(s), C(s){}
                  //^^^^ note this!

};

Just D(string s) : B(s), C(s) would not be enough: http://ideone.com/MPUPj

A(s) is also needed : http://ideone.com/DNLkA

See this topic for more detail: about virtual base class and virtual inheritance in C++