# std::unordered_set<Key,Hash,KeyEqual,Allocator>::end, std::unordered_set<Key,Hash,KeyEqual,Allocator>::cend

 iterator end() noexcept; (1) (since C++11) const_iterator end() const noexcept; (2) (since C++11) const_iterator cend() const noexcept; (3) (since C++11)

Returns an iterator to the element following the last element of the unordered_set.

This element acts as a placeholder; attempting to access it results in undefined behavior.

## Contents

(none)

### Return value

Iterator to the element following the last element.

Constant.

### Notes

Because both iterator and const_iterator are constant iterators (and may in fact be the same type), it is not possible to mutate the elements of the container through an iterator returned by any of these member functions.

### Example

#include <iostream>
#include <unordered_set>

struct Point { double x, y; };

int main()
{
Point pts[3] = {{1, 0}, {2, 0}, {3, 0}};

// points is a set containing the addresses of points
std::unordered_set<Point*> points = { pts, pts + 1, pts + 2 };

// Change each y-coordinate of (i, 0) from 0 into i^2 and print the point
for (auto iter = points.begin(); iter != points.end(); ++iter)
{
(*iter)->y = ((*iter)->x) * ((*iter)->x); // iter is a pointer-to-Point*
std::cout << "(" << (*iter)->x << ", " << (*iter)->y << ") ";
}
std::cout << '\n';

// Now using the range-based for loop, we increase each y-coordinate by 10
for (Point* i : points)
{
i->y += 10;
std::cout << "(" << i->x << ", " << i->y << ") ";
}
}

Possible output:

(3, 9) (1, 1) (2, 4)
(3, 19) (1, 11) (2, 14)