std::queue<T,Container>::size

 

C++

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Technical specifications

Symbols index

External libraries

 

Containers library

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array (C++11)

vector

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list

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std::queue

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queue::queue

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Capacity

queue::empty

queue::size

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queue::push

queue::emplace (C++11)

queue::pop

queue::swap (C++11)

Non-member functions

operator==operator!=operator<operator>operator<=operator>=operator<=> (C++20)

std::swap

Deduction guides(C++17)

 

size_type size() const;

Returns the number of elements in the underlying container, that is, c.size().

Parameters

(none)

Return value

The number of elements in the container.

Complexity

Constant.

Example

Run this code

#include <algorithm>
#include <iostream>
#include <queue>
 
int main()
{
    std::queue<int> container;
 
    std::cout << "Initially, container.size(): " << container.size() << '\n';
 
    for (int i = 0; i < 7; ++i)
        container.push(i);
 
    std::cout << "After adding elements, container.size(): " << container.size() << '\n';
}

Output:

Initially, container.size(): 0
After adding elements, container.size(): 7

See also

empty

checks whether the underlying container is empty (public member function)