可定义只能存在一个实例的类。
class GlobalInfo
{
public:
~GlobalInfo(){}
static GlobalInfo& instance();
private:
GlobalInfo(){}
static GlobalInfo *_instance;
};
GlobalInfo* GlobalInfo::_instance = NULL;
GlobalInfo& GlobalInfo::instance()
{
if (_instance == NULL)
{
_instance = new GlobalInfo();
}
return *_instance;
}