单例模式

class Singleton
{
public:
    static Singleton *getInstance();
private:
    Singleton();
    static Singleton *m_pInstance;
};

Singleton *Singleton::m_pInstance = 0;
Singleton::Singleton(){}
Singleton *Singleton::getInstance()
{
    if(0 == m_pInstance)
    {
        m_pInstance = new Singleton;
    }
    return m_pInstance;
}