134.异常类的处理

• 异常类

  #pragma once
  #include <initializer_list>
  using namespace std;
  
  class memerror
  {
  };
  
  class outerror
  {
  };
  
  class safeintarray
  {
  private:
      int *p;
      int n;
  
  public:
      safeintarray(int length);
      safeintarray(initializer_list<int> mylist);
      safeintarray();
      int &operator [](int num);
      ~safeintarray();
  };

• #include "safeintarray.h"
  
  
  
  safeintarray::safeintarray(int length)
  {
      if (length <= 0)
      {
          throw memerror();
      }
      this->p = new int[length] {0};
      this->n = length;
  }
  
  safeintarray::safeintarray(initializer_list<int> mylist)
  {
  }
  
  safeintarray::safeintarray()
  {
  }
  
  int & safeintarray::operator[] (int num)
  {
      // TODO: 在此处插入 return 语句
      if (num<0 || num>this->n - 1)
      {
          throw outerror();
      }
  
      return this->p[num];
  }
  
  
  safeintarray::~safeintarray()
  {
  }

• main.cpp

  #include <iostream>
  #include "safeintarray.h"
  using namespace std;
  
  void main()
  {
      try
      {
          safeintarray s1(5);
  
          cout << s1[5] << endl;
      }
      catch(outerror e)
      {
          cout << "内存分配错误" << endl;
      }
      catch (memerror e)
      {
          cout << "越界" << endl;
      }
  
      cin.get();
  }