如何从C ++内部类引用封装实例？

问题描述：

在C ++中，对象通过 this 引用自身。

In C++, an object refers to itself via this.

类指向其封装类的实例？

But how does an instance of an inner class refer to the instance of its enclosing class?

class Zoo
{
    class Bear 
    {
        void runAway()
        {
            EscapeService::helpEscapeFrom (
                this, /* the Bear */ 
                ??? /* I need a pointer to the Bear's Zoo here */);
        }
    };
};

EDIT

我对非静态内部类的工作原理的理解是 Bear 可以访问其 Zoo 的成员，因此它具有 Zoo 的隐式指针。我不想访问这种情况下的成员;我试图得到那个隐含的指针。

My understanding of how non-static inner classes work is that Bear can access the members of its Zoo, therefore it has an implicit pointer to Zoo. I don't want to access the members in this case; I'm trying to get that implicit pointer.

答

与Java不同，C ++中的内部类不会隐式引用它们的实例

Unlike Java, inner classes in C++ do not have an implicit reference to an instance of their enclosing class.

您可以通过传递一个实例来模拟它，有两种方式：

You can simulate this by passing an instance, there are two ways :

方法：

class Zoo
{
    class Bear 
    {
        void runAway( Zoo & zoo)
        {
            EscapeService::helpEscapeFrom (
                this, /* the Bear */ 
                zoo );
        }
    };
};

传递给构造函数：

class Zoo
{
    class Bear
    {
        Bear( Zoo & zoo_ ) : zoo( zoo_ ) {}
        void runAway()
        {
            EscapeService::helpEscapeFrom (
                this, /* the Bear */ 
                zoo );
        }

        Zoo & zoo;
    };
};

如何从C ++内部类引用封装实例？

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