虚类中含有虚函数的问题 还是又歧义的接口

[allen0228]

#include<iostream>
using namespace std;

class base{
    public:
		virtual void a(){cout<<"a() in base\n";}
		virtual void b(){cout<<"b() in base\n";}
		virtual void c(){cout<<"c() in base\n";}
		virtual void d(){cout<<"d() in base\n";}
		virtual void e(){cout<<"e() in base\n";}
		virtual void f(){cout<<"f() in base\n";}
};

class A:virtual public base{
    public:
		virtual void a(){cout<<"a() in A\n";}
		virtual void b(){cout<<"b() in A\n";}
		virtual void f(){cout<<"f() in A\n";}
};

class B:virtual public base{
    public:
		virtual void a(){cout<<"a() in B\n";}
		virtual void b(){cout<<"b() in B\n";}
		virtual void c(){cout<<"c() in B\n";}
};

class C:public A,public B{
    public:
		virtual void a(){cout<<"a() in C\n";}
		virtual void d(){cout<<"d() in C\n";}		
};

void main()
{
	C cc;
	base *pa = &cc;
	pa->a();
	pa->b();
	pa->c();
	pa->d();
	pa->e();
	pa->f();
}

错误描述
--------------------Configuration: ex539 - Win32 Debug--------------------
Compiling...
ex539.cpp
E:\c++\ex539.cpp(32) : error C2250: 'C' : ambiguous inheritance of 'A::b'
E:\c++\ex539.cpp(14) : see declaration of 'A'
E:\c++\ex539.cpp(32) : error C2250: 'C' : ambiguous inheritance of 'B::b'
E:\c++\ex539.cpp(21) : see declaration of 'B'
E:\c++\ex539.cpp(32) : warning C4250: 'C' : inherits 'B::c' via dominance
E:\c++\ex539.cpp(25) : see declaration of 'c'
E:\c++\ex539.cpp(32) : warning C4250: 'C' : inherits 'A::f' via dominance
E:\c++\ex539.cpp(18) : see declaration of 'f'
Error executing cl.exe.

ex539.exe - 2 error(s), 2 warning(s)

[zzq0406]

这是不是就是所谓的路径二 意啊！

[allen0228]

[Quote=引用 1 楼 zzq0406 的回复:]
这是不是就是所谓的路径二 意啊！
[/Quote]
yes 这个是多基派生中虚函数的二义性

[yshuise]

是的

[allen0228]

[Quote=引用 3 楼 yshuise 的回复:]
是的
[/Quote]

啥意思啊 怎么解决上面的错误啊

[zhaohongbo83]

这个要好好的看下

[lann64]

这里是设计意图的问题。
其中b()函数在A、B里都重写过，那么继承到C类时，希望是哪个b()呢？

这里要么去掉一个，要么在C里再重写b()。

#include<iostream>
using namespace std;

class base{
    public:
        virtual void a(){cout<<"a() in base\n";}
        virtual void b(){cout<<"b() in base\n";}
        virtual void c(){cout<<"c() in base\n";}
        virtual void d(){cout<<"d() in base\n";}
        virtual void e(){cout<<"e() in base\n";}
        virtual void f(){cout<<"f() in base\n";}
};

class A:virtual public base{
    public:
        virtual void a(){cout<<"a() in A\n";}
        virtual void b(){cout<<"b() in A\n";}
        virtual void f(){cout<<"f() in A\n";}
};

class B:virtual public base{
    public:
        virtual void a(){cout<<"a() in B\n";}
        virtual void b(){cout<<"b() in B\n";}
        virtual void c(){cout<<"c() in B\n";}
};

class C:public A,public B{
    public:
        virtual void a(){cout<<"a() in C\n";}
        virtual void b(){cout<<"b() in C\n";} //这样
        virtual void d(){cout<<"d() in C\n";}
};

int main()
{
    C cc;
    base *pa = &cc;
    pa->a();
    pa->b();
    pa->c();
    pa->d();
    pa->e();
    pa->f();
}

[allen0228]

还是有点不太明白
这样的话 为何还有warning
--------------------Configuration: ex539 - Win32 Debug--------------------
Compiling...
ex539.cpp
E:\c++\ex539.cpp(33) : warning C4250: 'C' : inherits 'B::c' via dominance
E:\c++\ex539.cpp(25) : see declaration of 'c'
E:\c++\ex539.cpp(33) : warning C4250: 'C' : inherits 'A::f' via dominance
E:\c++\ex539.cpp(18) : see declaration of 'f'
Linking...

ex539.exe - 0 error(s), 2 warning(s)

[luojc714]

不懂，顶一个！

[lann64]

[Quote=引用 7 楼 suiye 的回复:]
还是有点不太明白
这样的话 为何还有warning
--------------------Configuration: ex539 - Win32 Debug--------------------
Compiling...
ex539.cpp
E:\c++\ex539.cpp(33) : warning C4250: 'C' : inherits 'B::c' via dominance
E:\c++\ex539.cpp(25) : see declaration of 'c'
E:\c++\ex539.cpp(33) : warning C4250: 'C' : inherits 'A::f' via dominance
E:\c++\ex539.cpp(18) : see decla…
[/Quote]
是的，c()和f()还是隐含着二义的，虽然一个是来自直接父类、一个是来自父类的父类

[nullah]

[Quote=引用 6 楼 lann64 的回复:]
这里是设计意图的问题。
其中b()函数在A、B里都重写过，那么继承到C类时，希望是哪个b()呢？

这里要么去掉一个，要么在C里再重写b()。

C/C++ code#include<iostream>
using namespace std;

class base{
public:
virtual void a(){cout<<"a() in base\n";}
virtual void b(){cout<<"b() in base\n";}
virtual void c(){cout<<"c() in base\n";}
virtual void d(){cout<<"…
[/Quote]
up

[zgy1353246]

学习了

[lq651659889]

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