模板容器iterator使用

示例：

template <typename T> 
struct tNode
{
    T Data;                      
    list<tNode<T>*> SubNodes;       

    tNode(const T& theData)
    {
        this->Data = theData;
        SubNodes(INIT_CAPACITY);   //INIT_CAPACITY is 10
    }

};

list<tNode<T>*>::iterator it(); //编译出错
typename list<tNode<T>*>::iterator it //编译通过