std::unordered_multiset<Key,Hash,KeyEqual,Allocator>::empty
Min standard notice:
Checks if the container has no elements, i.e. whether begin() == end().
# Declarations
bool empty() const noexcept;
(since C++11)
# Return value
true if the container is empty, false otherwise.
# Example
#include <iostream>
#include <unordered_set>
int main()
{
std::unordered_multiset<int> numbers;
std::cout << std::boolalpha;
std::cout << "Initially, numbers.empty(): " << numbers.empty() << '\n';
numbers.insert(42);
numbers.insert(19937);
std::cout << "After adding elements, numbers.empty(): " << numbers.empty() << '\n';
}