類繼承：靜態成員和虛擬方法

Question

我正在一個異常類，簡單地報告了cout問題，退出程序，就像這樣：

class Exception { 
protected: 
    short code; 
    string text; 
public: 
    friend ostream& operator <<(ostream& out, const Exception& p_exception) { 
     return out << p_exception.text; 
    } 
    void execute() { cout << text; exit(code); 
}; 

，它的具體的例子：

class IndexOutOfBoundsException : public Exception { 
public: 
    IndexOutOfBoundsException() { 
     this->text = "\nERR: An unsuccessful attempt was made to access the index outside the bounds of the array!"; 
     code = 1; 
    } 
}; 
class IndexOfEmptyFieldException : public Exception { 
public: 
    IndexOfEmptyFieldException() { 
     this->text = "\nERR: An unsuccessful attempt was made to access the index of an empty field!"; 
     code = 2; 
    } 
}; 
class AllocationFailureException : public Exception { 
public: 
    AllocationFailureException() { 
     this->text = "\nERR: An unsuccessful attempt was made to allocate dynamic memory!"; 
     code = 3; 
    } 
}; 

在我的腦海中，它看起來很整齊，但現在它似乎不像一個好的OOP示例。當我考慮結束時，我想我可以以某種方式使用靜態成員，例如使int code;成爲繼承類的特定靜態變量。或者，我可以用= 0使方法void generate();成爲純虛函數，這是我的第一個想法。

我的問題是：是否有可能使這個解決方案成爲一個更好的OOP示例和/或我是否忽略了OOD的一般要點？

Answer 1

下面是一個例子，即減少對象足跡和從擲子句移動存儲器分配程：

class Exception { 
protected: 
    short code; 
    const string &text; 
    Exception(short code, const string &text) : 
    code(code), text(text) 
    {} 
... 
} 

class IndexOutOfBoundsException : public Exception { 
private: 
    static const string c_text = "\nERR: An unsuccessful attempt was made to access the index outside the bounds of the array!"; 
public: 
    IndexOutOfBoundsException() : Exception(1, c_text) 
    { } 
};