在c中使用“This”指针++

但我发现了这样一句话:

  // Return an object that defines its own operator[] that will access the data.
  // The temp object is very trivial and just allows access to the data via 
  // operator[]
  VectorDeque2D_Inner_Set<T> operator[](unsigned int first_index) { 
    return VectorDeque2D_Inner_Set<T>(*this, first_index);
  }

那是干什么用的?它是否以某种方式增加了这个操作符的值,如果是,为什么??

编辑1
以下是完整的列表,以获取更多信息。函数位于类的底部。注意,我将变量从x重命名为index,并重命名了模板化的内部类。我忘了将typecast放到模板化的内部类中,这是我在这次更新中添加的。

现在有什么想法吗?

template <typename T>
class Container
{
private:
    // ...


public:

    // Proxy object used to provide the second brackets
    template <typename T>
    class OperatorBracketHelper
    {
        Container<T> & parent;
        size_t firstIndex;
    public:
        OperatorBracketHelper(Container<T> & Parent, size_t FirstIndex) : parent(Parent), firstIndex(FirstIndex) {}

        // This is the method called for the "second brackets"
        T & operator[](size_t SecondIndex)
        {
            // Call the parent GetElement method which will actually retrieve the element
            return parent.GetElement(firstIndex, SecondIndex);
        }

    }

    // This is the method called for the "first brackets"
    OperatorBracketHelper<T> operator[](size_t FirstIndex)
    {
        // Return a proxy object that "knows" to which container it has to ask the element
        // and which is the first index (specified in this call)
        return OperatorBracketHelper<T>(*this, FirstIndex);
    }

    T & GetElement(size_t FirstIndex, size_t SecondIndex)
    {
        // Here the actual element retrieval is done
        // ...
    }
}