std::unordered_multimap::size

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

 

std::unordered_multimap

Member functions

unordered_multimap::unordered_multimap

unordered_multimap::~unordered_multimap

unordered_multimap::operator=

unordered_multimap::get_allocator

Iterators

unordered_multimap::begin unordered_multimap::cbegin

unordered_multimap::end unordered_multimap::cend

Capacity

unordered_multimap::erase

unordered_multimap::size

unordered_multimap::max_size

Modifiers

unordered_multimap::clear

unordered_multimap::insert

unordered_multimap::emplace

unordered_multimap::emplace_hint

unordered_multimap::erase

unordered_multimap::swap

Lookup

unordered_multimap::count

unordered_multimap::find

unordered_multimap::equal_range

Bucket interface

unordered_multimap::begin2

unordered_multimap::end2

unordered_multimap::bucket_count

unordered_multimap::max_bucket_count

unordered_multimap::bucket_size

unordered_multimap::bucket

Hash policy

unordered_multimap::load_factor

unordered_multimap::max_load_factor

unordered_multimap::rehash

unordered_multimap::reserve

Observers

unordered_multimap::hash_function

unordered_multimap::key_eq

 

size_type size() const;		(since C++11)

Returns the number of elements in the container, i.e. std::distance(begin(), end()).

Parameters

(none)

Return value

the number of elements in the container

Exceptions

noexcept specification:  

noexcept

  (since C++11)

Complexity

Constant

Example

The following code uses size to display the number of elements in a std::unordered_multimap<int>:

run this code

#include <unordered_multimap>
#include <iostream>
 
int main()
{
    std::unordered_multimap<int, char> nums {{1, 'a'}, {3, 'b'}, {5, 'c'}, {7, 'd'}};
 
    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output:

nums contains 4 elements.

See also

empty	checks whether the container is empty (public member function)
max_size	returns the maximum possible number of elements (public member function)