std::map<Key,T,Compare,Allocator>::empty

bool empty() const;

Vérifie si le conteneur n'a aucun élément, c'est-à-dire si begin() == end().

Valeur de retour

true si le conteneur est vide, false sinon.

Complexité

Constante.

Exemple

#include <iostream>
#include <map>
#include <utility>
int main()
{
    std::map<int,int> numbers;
    std::cout << std::boolalpha;
    std::cout << "Initially, numbers.empty(): " << numbers.empty() << '\n';
    numbers.emplace(42, 13);
    numbers.insert(std::make_pair(13317, 123));
    std::cout << "After adding elements, numbers.empty(): " << numbers.empty() << '\n';
}

Initially, numbers.empty(): true
After adding elements, numbers.empty(): false

Voir aussi