Singleton

#include <iostream>
 
class Singleton {
 
private:
	Singleton(const int value) : m_value(value) {}
 
	int m_value = 0;
 
public:
	Singleton(const Singleton& other) = delete;
 
	void operator=(const Singleton&) = delete;
 
	static Singleton& getInstance(const int value);
 
	int getValue() {
		return m_value;
	}
 
};
 
Singleton& Singleton::getInstance(const int value) {
 
	static Singleton instance(value);
 
	return instance;
}
 
int main() {
	Singleton& singleton = Singleton::getInstance(42);
	std::cout << "Singleton value: " << singleton.getValue() << std::endl;
 
	return 0;
}