std::queue<T,Container>::empty
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
#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
returns the number of elements (public member function) |
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