重载预增量运算符

Question

Here is the declaration:

 Iterator operator++();//pre-increment

Here is the definition:

LinkedList::Iterator& LinkedList::Iterator::operator++(){
   return Iterator(current->next);//this is giving me an error
}

Here is how the class looks

class LinkedList{
public:
    Node struct{
      /*contains pointer to next node and an integer value*/
      int val;
      Node* next;
    };
    class Iterator{
    public:
      Iterator& operator++();//pre-increment
    protected:
      Node* current;//points to current node
    }
} 

Answer 1

You create a new iterator object, and (attempt to) return a reference to that.

The prefix-increment operator modifies this object, and should return a reference to itself:

current = current->next;  // TODO: Add checking for not going out of bounds or dereferencing a null pointer
return *this;