# std::queue<T,Container>::empty

From cppreference.com
< cpp‎ | container‎ | queue

bool empty() const; |  | (until C++20)
[[nodiscard]] bool empty() const; |  | (since C++20)

Checks if the underlying container has no elements, i.e. whether c.empty().

### Parameters

(none)

### Return value

true if the underlying container is empty, false otherwise

### Complexity

Constant

### Example

Run this code

    #include <algorithm>
    #include <iostream>
    #include <queue>

    int main()
    {
        std::cout << std::boolalpha;

        std::queue<int> container;

        std::cout << "Initially, container.empty(): " << container.empty() << '\n';

        container.push(42);
        std::cout << "After adding elements, container.empty(): " << container.empty() << '\n';
    }

Output:

    Initially, container.empty(): true
    After adding elements, container.empty(): false

### See also

size | returns the number of elements (public member function)

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