iterator begin() noexcept; | (1) | (since C++11) |
const_iterator begin() const noexcept; | (2) | (since C++11) |
const_iterator cbegin() const noexcept; | (3) | (since C++11) |
Returns an iterator to the first element of the unordered_multiset
.
If the unordered_multiset
is empty, the returned iterator will be equal to end()
.
(none).
Iterator to the first element.
Constant.
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.
#include <iostream> #include <iterator> #include <string> #include <unordered_set> int main() { const std::unordered_multiset<std::string> words = { "some", "words", "to", "count", "count", "these", "words" }; for (auto it = words.begin(); it != words.end(); ) { auto count = words.count(*it); std::cout << *it << ":\t" << count << '\n'; std::advance(it, count); // all count elements have equivalent keys } }
Possible output:
some: 1 words: 2 to: 1 count: 2 these: 1
(C++11) | returns an iterator to the end (public member function) |
(C++11)(C++14) | returns an iterator to the beginning of a container or array (function template) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/container/unordered_multiset/begin