我正在看这个cpp闪电谈话video它在0:37显示这段代码template>classQScopedPointer{typedefT*QScopedPointer::*RestrictedBool;//howdoesthiswork?//whynotQScopedPointersinceQScopedPointerisatemplate?public:inlineoperatorRestrictedBool()const{returnisNull()?Q_NULLPTR:&QScopedPointer::d;}inlineboolisNull()const{return!d;}pro