std::unordered_multiset<Key,Hash,KeyEqual,Allocator>::begin, std::unordered_multiset<Key,Hash,KeyEqual,Allocator>::cbegin
iterator begin() noexcept; | (since C++11) | |
const_iterator begin() const noexcept; | (since C++11) | |
const_iterator cbegin() const noexcept; | (since C++11) |
Returns an iterator to the first element of the container.
If the container is empty, the returned iterator will be equal to end()
.
Parameters
(none).
Return value
Iterator to the first 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
#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 cnt = words.count(*it); std::cout << *it << ":\t" << cnt << '\n'; std::advance(it, cnt); // all cnt elements have equivalent keys } }
Possible output:
some: 1 words: 2 to: 1 count: 2 these: 1
See also
returns an iterator to the end (public member function) |
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