虚拟和非虚拟继承的混合(mixture of virtual and non-virtual inheritance)

 在尝试更深入地分析C ++的继承机制时，我偶然发现了以下示例： 
 
#include<iostream>

using namespace std;

class Base {
public:
    virtual void f(){
    cout << "Base.f" << endl; 
    }
};

class Left : public Base { //NOT VIRTUAL!!!
public:
void g(){ 
        f();
    }     
};

class Right : public Base{
public:
    virtual void f(){
    cout << "Right.f" << endl; 
    }
};

class Bottom : public Left, public Right{
public:
    Bottom(int arg){ }
    //void f() { }
};

int main(int argc,char **argv)
{
    Bottom* b = new Bottom(23);
    b->g();
}
 
 很明显，打电话 
 
b->f()
 
 是不明确的，所以对象底部没有唯一的方法f() 。 现在，打电话 
 
b->g()
 
 工作得很好，打印 
 
Base.f
 
 好吧，据我所知： 
 
 
 
 static类型是Bottom，所以我们称之为g()方法，因为它是非虚拟的 
 
 
 g()方法是从Left继承的，所以我们称之为继承方法 
 
 
 现在，左边的g()尝试调用虚方法f() 。 根据C ++ sepcification，我们调用f()方法的动态类型的指针（这是底部） 
 
 
 但是底部没有方法f() ......至少不是唯一的方法。 为什么这个程序执行Left::Base::f()而不是Right::Base::f()或者为什么它只是没有说明调用f()与Bottom不一致？ 

while trying to analyse in greater depth inheritance mechanism of C++ I stumbled upon the following example:
 
#include<iostream>

using namespace std;

class Base {
public:
    virtual void f(){
    cout << "Base.f" << endl; 
    }
};

class Left : public Base { //NOT VIRTUAL!!!
public:
void g(){ 
        f();
    }     
};

class Right : public Base{
public:
    virtual void f(){
    cout << "Right.f" << endl; 
    }
};

class Bottom : public Left, public Right{
public:
    Bottom(int arg){ }
    //void f() { }
};

int main(int argc,char **argv)
{
    Bottom* b = new Bottom(23);
    b->g();
}
 
It is clear that calling
 
b->f()
 
is ambiguous, so there is no unique method f() on object Bottom. Now, calling
 
b->g()
 
works fine and prints
 
Base.f
 
Well, as far as I see this:
 
 
 
static type is Bottom, so we call its g() method, as it is non-virtual
 
 
g() method is inherited from Left, so we call this inherited method
 
 
Now, g() in Left tries to call virtual method f(). According to C++ sepcification, we call f() method of a dynamic type of our pointer (which is Bottom)
 
 
BUT Bottom does not have method f()... at least not a unique one. Why does this program executes Left::Base::f() rather than Right::Base::f() or why does it simply not states that call to f() is ambiguous from Bottom?

原文：https://stackoverflow.com/questions/10166313