table of contents
std::queue::empty(3) | C++ Standard Libary | std::queue::empty(3) |
NAME¶
std::queue::empty - std::queue::empty
Synopsis¶
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)
2022.07.31 | http://cppreference.com |