std::multiset end() method

od C++11

// Non const version
iterator end() noexcept;

// Const version
iterator end() const noexcept;

// Const version
const_iterator cend() const noexcept;

do C++11

// Non const version
iterator end();

// Const version
const_iterator cend();

Returns an iterator

to the element past-the-end of the array. If the array is empty, the returned iterator will be equal to begin().

Attempting to dereference a past-the-end iterator is undefined behaviour

.

Parameters

(none)

Return value

Iterator to the first element.

Exceptions

(none)

Complexity

Constant - O(1).

Difference between end and cend

For a const container c, end and cend are the same - c.end() == c.cend()

For non-const container of type c they return different iterators:

Non const container

end

#include <multiset>

int main()
{
    std::multiset<int> multiset = { 1, 2, 3 };
    auto it = arr.end(); // Type: std::multiset<int>::iterator
    *std::prev(it) = 5; // ✔ Ok
}

cend

#include <multiset>

int main()
{
    std::multiset<int> multiset = { 1, 2, 3 };
    auto it = arr.cend(); // Type: std::multiset<int>::const_iterator
    *std::prev(it) = 5; // ❌ Error! 
}

Const container

end

#include <map>

int main()
{
    const std::multiset<int, float> map = { {1, 1.f}, {2, 3.f}, {5, 8.f} };
    auto it = arr.end(); // Type: std::multiset<int>::const_iterator
    *std::prev(it) = 5; // ❌ Error! 
}

cend

#include <map>

int main()
{
    const std::multiset<int, float> map = { {1, 1.f}, {2, 3.f}, {5, 8.f} };
    auto it = arr.cend(); // Type: std::multiset<int>::const_iterator
    *std::prev(it) = 5; // ❌ Error! 
}

Example

Main.cpp

#include <iostream>
#include <iterator>
#include <set>
#include <string>
 
int main()
{
    const std::multiset<std::string> words = {
        "some", "not", "sorted", "words",
        "will", "come", "out", "sorted",
    };
 
    for (auto it = words.begin(); it != words.end(); ) {
        auto cnt = words.count(*it);
        std::cout << *it << ":\t" << cnt << '\n';
        std::advance(it, cnt); // all cnt elements have equivalent keys
    }
}

Output

come:	1
not:	1
out:	1
some:	1
sorted:	2
will:	1
words:	1