std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::size

 

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unordered_multimap (C++11)

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flat_multimap (C++23)

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std::flat_multimap

Member types
Member functions
flat_multimap::flat_multimap	flat_multimap::operator=
Iterators
flat_multimap::beginflat_multimap::cbegin flat_multimap::endflat_multimap::cend	flat_multimap::rbeginflat_multimap::crbegin flat_multimap::rendflat_multimap::crend
Capacity
flat_multimap::size flat_multimap::max_size	flat_multimap::empty
Modifiers
flat_multimap::clear flat_multimap::erase flat_multimap::swap flat_multimap::extract flat_multimap::replace	flat_multimap::insert flat_multimap::insert_range flat_multimap::emplace flat_multimap::emplace_hint
Lookup
flat_multimap::count flat_multimap::find flat_multimap::contains	flat_multimap::equal_range flat_multimap::lower_bound flat_multimap::upper_bound
Observers
flat_multimap::key_comp flat_multimap::keys	flat_multimap::value_comp flat_multimap::values
Non-member functions
operator==operator<=> (C++23)(C++23)	swap(std::flat_multimap) (C++23) erase_if(std::flat_multimap) (C++23)
Helper classes
uses_allocator<std::flat_multimap> (C++23)
Tags
sorted_equivalent (C++23)	sorted_equivalent_t (C++23)
Deduction guides

 

size_type size() const noexcept;		(since C++23)

Returns the number of elements in the container adaptor. Equivalent to return c.keys.size().

Parameters

(none)

Return value

The number of elements in the container adaptor.

Complexity

Constant.

Example

The following code uses size to display the number of elements in a std::flat_multimap:

Run this code

#include <iostream>
#include <flat_map>
 
int main()
{
    std::flat_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 adaptor is empty (public member function)
sizessize (C++17)(C++20)	returns the size of a container or array (function template)
max_size	returns the maximum possible number of elements (public member function)