範例

class Base {
public:
void fnc();
};

class Derived: public Base {
public:
void fnc(){}
};

void callDerivedFunction(Base *ptr){

Derived *dp = (Derived*) ptr;
dp->fnc();

}

解決方案

請將一個類別的指標強制轉型成它並未繼承的類別指標。若要避免錯誤，請勿將指標用於向下強制轉型。請改用虛擬函數。

class Base {
public:
virtual void fnc();
};

class Derived: public Base {
public:
virtual void fnc(){}
};

void callDerivedFunction(Base *ptr){

ptr->fnc();

}