Class继承：静态成员和虚方法

Question

我正在做一个例外 class，它只是在 cout 上报告问题并退出程序，如下所示：

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);
};

具体例子：

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;
    }
};

在我看来，这一切看起来都非常整洁，但现在它似乎不是一个很好的 OOP 示例。当我仔细考虑时，我突然想到我可以以某种方式使用静态成员，比如使 int code; 成为特定于继承 classes 的静态变量。或者，我可以使方法 void generate(); 成为带有 = 0 的纯虚函数，这是我的第一个想法。

我的问题是：是否有可能使此解决方案成为更好的 OOP 示例and/or我是否遗漏了 OOD 的一般要点？

Answer 1

这是一个示例，它减少了对象占用空间并将内存分配从 throw 子句移开：

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)
  { }
};

Class继承：静态成员和虚方法

Class inheritance: static members and virtual methods

c++

oop

inheritance

virtual-functions