单例模式：饿汉式

单例模式全局仅一个实例，用于获取公共的内容

头文件mglobalinfomgr.h

class MGlobalInfoMgr
{MGlobalInfoMgr();~MGlobalInfoMgr();
public:static MGlobalInfoMgr* GetInstance();
private:static MGlobalInfoMgr* _instance;
};

源文件mglobalinfomgr.cpp

MGlobalInfoMgr* MGlobalInfoMgr::_instance = NULL;
MGlobalInfoMgr::MGlobalInfoMgr()
{cout<<"new mgr";
}
MGlobalInfoMgr::~MGlobalInfoMgr()
{//
}
MGlobalInfoMgr* MGlobalInfoMgr::GetInstance()
{if(!_instance){_instance = new MGlobalInfoMgr();}return _instance;
}