C++异常层次结构

 #define _CRT_SECURE_NO_WARNINGS
 #include <iostream>

 using namespace std;

 class MyArray
 {
 public:
     MyArray(int len);
     ~MyArray();

 public:
     int & operator[](int index);
     int getlen();

 public:
     class eSize
     {
     public:
         eSize(int len)
         {
             size = len;
         }
         virtual void printfErr()
         {
             cout << "size:" << size <<endl;
         }
     protected:
         int size;
     private:
     };

     class eNegative : public eSize
     {
     public:
         eNegative(int size):eSize(size)
         {
             ;
         }
         virtual void printfErr()
         {
             cout << "eNegative 异常 size:" << size << endl;
         }
     protected:
     private:
     };
     class eZero : public eSize
     {
     public:
         eZero(int size):eSize(size)
         {
             ;
         }
         virtual void printfErr()
         {
             cout << "eZero 异常 size:" << size << endl;
         }
     protected:
     private:
     };
     class eTooBig : public eSize
     {
     public:
         eTooBig(int size):eSize(size)
         {
             ;
         }
         virtual void printfErr()
         {
             cout << "eTooBig 异常 size:" << size << endl;
         }
     protected:
     private:
     };
     class eTooSmall : public eSize
     {
     public:
         eTooSmall(int size):eSize(size)
         {
             ;
         }
         virtual void printfErr()
         {
             cout << "eTooSmall 异常 size:" << size << endl;
         }
     protected:
     private:
     };

 protected:
 private:
     int *m_space;
     int m_len;
 };

 MyArray::MyArray(int len)
 {
     if (len < )
     {
         throw eNegative(len);
     }
     else if (len == )
     {
         throw eZero(len);
     }
     else if (len > )
     {
         throw eTooBig(len);
     }
     else if (len < )
     {
         throw eTooSmall(len);
     }

     m_len = len;
     m_space = new int[len];
 }

 MyArray::~MyArray()
 {
     if (m_space != NULL)
     {
         delete[]m_space;
         m_space =  NULL;
         m_len = ;
     }

 }
 int& MyArray::operator[](int index)
 {
     return  m_space[index];
 }
 int MyArray::getlen()
 {
     return m_len;
 }

 int main(void)
 {
     try
     {
         MyArray a();
         for (int i=; i<a.getlen(); i++)
         {
             a[i] = i+;
             printf("%d ", a[i]);
         }
     }
     catch (MyArray::eSize& e)
     {
         e.printfErr();
     }

     catch (...)
     {
         ;
     }

     cout << "Hello World!" << endl;
     system("pause");
     return ;
 }