如何获取列表中被推回的元素的地址，在恒定时间内，在 c++ stl 中？

Question

list<int> l;
list<int>::iterator lastElement;
lastElement=l.end()
l.push_back(10);
cout<<"Address of the element 10 in the list is"<<&lastElement<<endl;

Is the above way the correct way to get the address of the last element of a list in constant time. I know there are many other methods but I want a method that gives the address in constant time.

Answer 1

How to get the address of the element which is pushed back in the list, In constant time,in c++ stl?

After pushing the element, use std::list::back to get reference to the element. Then use the operator & to get the address of the element (or use std::addressof if the operator is overloaded, which is unusual).

Is the above way the correct way to get the address of the last element of a list

No. There are several problems:

• std::list:end returns an iterator to the element past the end of the list; not an iterator to the last element.
• You take the iterator before pushing an element into the list. The iterator cannot possibly be to an element that you later push to the list.
• You apply operator & on the iterator. The result is the address of the iterator; not the address of the element that the iterator points to.