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;
}