std::queue::empty(3)

💖 NAME 💖

You're on the std::queue::empty(3) page in the C++ Standard Libary, bestie. The name is std::queue::empty — and the one-liner? Also std::queue::empty. No cap, that's the whole name section. Iconic.

🦋 Synopsis 🦋

Two eras, two signatures, same "is it empty tho" energy:

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

It checks if the underlying container has no elements. Equivalent to return c.empty();.

🍓 Parameters 🍓

• (none) — literally no parameters. Not a single one. The parameter list is giving empty-queue energy.

🌈 Return value 🌈

• true if the underlying container is empty.
• false otherwise.

🧚 Complexity 🧚

Constant. That's the whole complexity note, bestie.

🔥 Example 🔥

       // Run this code

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

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

            std::queue<int> queue;

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

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

💅 Output 💅

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

👑 See also 👑

• size — returns the number of elements (public member function).
• empty — checks whether the container is empty (C++17) (function template).

That's the whole page, bestie. Source/version/date: http://cppreference.com, 2024.06.10, std::queue::empty(3). Slay. 💅