class ClassB; class ClassA{ public: ClassA(); private: std::unique_ptr<ClassB> u; // NG std::shared_ptr<ClassB> s; // OK }
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class ClassB; class ClassA{ public: ClassA(); ~ClassA(); ←これでunique_ptrもOK private: std::unique_ptr<ClassB> u; // OK std::shared_ptr<ClassB> s; // OK }