Design pattern.
A Singleton is a design pattern that ensures a class has only one instance and provides a global point of access to that instance.
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| #include <iostream>
class Singleton {
private:
static Singleton* _instance;
Singleton() {
std::cout << "Singleton created\n";
}
Singleton(const Singleton& rhs) = delete;
Singleton& operator=(const Singleton& rhs) = delete;
public:
static Singleton* getInstance() {
if (_instance == nullptr) {
_instance = new Singleton();
}
return _instance;
}
};
Singleton* Singleton::_instance = nullptr;
int main() {
Singleton* a = Singleton::getInstance();
Singleton* b = Singleton::getInstance();
Singleton* c = Singleton::getInstance();
std::cout << "Memory addresses of a, b and c: " << a << ' ' << b << ' ' << c << '\n';
}
|
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| Singleton created
Memory addresses of a, b and c: 0x17662b0 0x17662b0 0x17662b0
|
