NAME¶

std::unordered_set::end, - std::unordered_set::end,

Synopsis¶

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.

range-begin-end.svg

Parameters¶

(none)

Return value¶

Iterator to the element following the last element.

Complexity¶

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¶

// Run this code

#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)

See also¶

begin returns an iterator to the beginning
cbegin (public member function)
end
cend returns an iterator to the end of a container or array
(C++11) (function template)
(C++14)