std::flat_set<Key,Compare,KeyContainer>::empty - cppreference.com
From cppreference.com
bool empty() const noexcept; |
(since C++23) | |
Checks if the underlying container has no elements. Equivalent to: return begin() == end();.
Return value
true if the underlying container is empty, false otherwise.
Complexity
Constant.
Example
The following code uses empty to check if a std::flat_set<int> contains any elements:
#include <iostream> #include <flat_set> int main() { std::flat_set<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) [edit] | |
| checks whether the container is empty (function template) [edit] |