std::flat_multiset<Key,Compare,KeyContainer>::empty
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< cpp | container | flat multiset
C++
Containers library
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(C++26)
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bool empty() const noexcept; |
(since C++23) | |
Checks if the underlying container has no elements. Equivalent to: return begin() == end();
Parameters
(none)
Return value
true if the underlying container is empty, false
Complexity
Constant.
Example
The following code uses empty to check if a
std::flat_multiset<int>
Run this code
#include <iostream> #include <flat_set> int main() { std::flat_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'; }
Output:
Initially, numbers.empty(): true After adding elements, numbers.empty(): false
See also
| returns the number of elements (public member function) |
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(C++17)
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checks whether the container is empty (function template) |