类开发中异常的结构设置

#include <iostream>
using namespace std;

class MyArray
{
public:
    MyArray(int len);
    ~MyArray();
public:
    int & operator[](int index);
    int getLen();

    class eSize
    {
    public:
        eSize(int size)
        {
            m_size = size;
        }
        virtual void printErr()
        {
            cout << "size:" << m_size << " ";
        }
    protected:
        int m_size;
    };
    class eNegative : public eSize
    {
    public:
        eNegative(int size) : eSize(size)
        {
            ;
        }
        virtual void printErr()
        {
            cout << "eNegative 类型 size:" << m_size << " ";
        }
    };
    class eZero : public eSize
    {
    public:
        eZero(int size) : eSize(size)
        {
            ;
        }
        virtual void printErr()
        {
            cout << "eZero 类型 size:" << m_size << " ";
        }
    };
    class eTooBig : public eSize
    {
    public:
        eTooBig(int size) : eSize(size)
        {
            ;
        }
        virtual void printErr()
        {
            cout << "eTooBig 类型 size:" << m_size << " ";
        }
    };
    class eTooSmall : public eSize
    {
    public:
        eTooSmall(int size) : eSize(size)
        {
            ;
        }
        virtual void printErr()
        {
            cout << "eTooSmall 类型 size:" << m_size << " ";
        }
    };

private:
    int *m_space;
    int m_len;
};


MyArray::MyArray(int len)
{
    if (len  < 0)
    {
        throw eNegative(len);
    }
    else if (len == 0)
    {
        throw eZero(len);
    }
    else if (len > 1000)
    {
        throw eTooBig(len);
    }
    else if (len < 3)
    {
        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 = 0;
    }
}

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

int MyArray::getLen()
{
    return m_len;
}

void main()
{

    try
    {
        MyArray a(-5);
        for (int i=0; i<a.getLen(); i++)
        {
            a[i] = i+1;
            printf("%d ", a[i]);
        }
    }
    catch(MyArray::eSize &e)
    {
        //cout <<  "len的大小: " << e.eSize();
        e.printErr();
    }
    catch (...)
    {
    }


    cout<<"hello..."<<endl;
    system("pause");
    return ;
}

// 不推荐
void main51()
{
    
    try
    {
        MyArray a(-5);
        for (int i=0; i<a.getLen(); i++)
        {
            a[i] = i+1;
            printf("%d ", a[i]);
        }
    }
    catch(MyArray::eNegative e)
    {
        cout << "eNegative 类型异常" << endl;
    }
    catch(MyArray::eZero e)
    {
        cout << "eZero 类型异常" << endl;
    }
    catch(MyArray::eTooBig e)
    {
        cout << "eTooBig 类型异常" << endl;
    }
    catch(MyArray::eTooSmall e)
    {
        cout << "eTooSmall 类型异常" << endl;
    }
    
    catch (...)
    {
    }
    

    cout<<"hello..."<<endl;
    system("pause");
    return ;
}