singleton.cpp

class singleton
{
	private static singleton *_instance = null;
protected:
	singleton()
	{
		if(_instance)
		{
			throw std::logic_error("ss");
		}
	}

	~singleton()
	{
		if(_instance)
		{
			singleton* instance_copy = _instance;
			_instance = nullptr;
			delete instance_copy;
		}
	}

public:
	static singleton& getInstance()
	{
		if(!_instance)
		{
			_instance = new singleton;
		}
		return *_instance;
	}
};