c++ - 内部类和访问外部成员

Question

我对同一个标题有疑问 here但是现在，正如我将在下面的代码中展示的那样，这似乎与我在第一个同标题问题中向我解释的方式相反。好的代码:

class LINT_rep
{
private:
    char* my_data_; //stores separately every single digit from a number
public:
    class Iterator:public iterator<bidirectional_operator_tag,char>
        {
private: 
char* myData_
public:
        Iterator(const LINT_rep&);
    };
};

#include "StdAfx.h"
#include "LINT_rep.h"


LINT_rep::Iterator::Iterator(const LINT_rep& owner):myData_(nullptr)
{
    myData_ = owner.my_data_; /*
        HERE I'M ACCESSING my_data WHICH IS PRIVATE AND THIS   
        CODE COMPILES ON VS2010 ULTIMATE BUT IT SHOULDN'T  
        BECAUSE my_data IS PRIVATE AND OTHER CLASS SHOULDN'T  
        HAVE ACCESS TO IT'S PRIVATE MEMB. AS EXPLAINED TO ME IN  
        QUESTION TO WHICH I;VE PROVIDED LINK. */
}

代码中的问题。谢谢。

Answer 1

在即将推出的 C++0x 标准中，嵌套类对封闭类成员的访问权限正在发生变化。在当前标准中，11.8 说:

The members of a nested class have no special access to members of an enclosing class

在 C++0x 的草案中，这变成了

A nested class is a member and as such has the same access rights as any other member

一些编译器正在采用新的访问规则；从你的问题来看，我猜 VS2010 可以，而且我从经验中知道 GCC 已经做了一段时间。