list2009.cpp

teach yourself C++ in 21 days 第五版

#include <iostream>
using namespace std;

const int DefaultSize = 10;
class xBoundary {};

template <class T>
class Array
{
  public:
    // constructors
    Array(int itsSize = DefaultSize);
    Array(const Array &rhs);
    ~Array() { delete [] pType;}

    // operators
    Array& operator=(const Array<T>&);
    T& operator[](int offSet);
    const T& operator[](int offSet) const;

    // accessors
    int GetitsSize() const { return itsSize; }

    // friend function
    friend ostream& operator<< (ostream&, const Array<T>&);

    // define the exception classes

    class xSize {};

  private:
    int *pType;
    int  itsSize;
};

template <class T>
Array<T>::Array(int size):
   itsSize(size)
{
   if (size <10 || size > 30000)
      throw xSize();
   pType = new T[size];
   for (int i = 0; i<size; i++)
      pType[i] = 0;
}

template <class T>
Array<T>& Array<T>::operator=(const Array<T> &rhs)
{
   if (this == &rhs)
      return *this;
   delete [] pType;
   itsSize = rhs.GetitsSize();
   pType = new T[itsSize];
   for (int i = 0; i < itsSize; i++)
      pType[i] = rhs[i];
}
template <class T>
Array<T>::Array(const Array<T> &rhs)
{
   itsSize = rhs.GetitsSize();
   pType = new T[itsSize];
   for (int i = 0; i < itsSize; i++)
      pType[i] = rhs[i];
}

template <class T>
T& Array<T>::operator[](int offSet)
{
   int size = GetitsSize();
   if (offSet >= 0 && offSet < GetitsSize())
      return pType[offSet];
   throw xBoundary();
   return pType[0];
}

template <class T>
const T& Array<T>::operator[](int offSet) const
{
   int mysize = GetitsSize();
   if (offSet >= 0 && offSet < GetitsSize())
      return pType[offSet];
   throw xBoundary();
}

template <class T>
ostream& operator<< (ostream& output, const Array<T>& theArray)
{
   for (int i = 0; i < theArray.GetitsSize(); i++)
      output << "[" << i << "] " << theArray[i] << endl;
   return output;
}


int main()
{
   try
   {
      Array<int> intArray(9);
      for (int j = 0; j < 100; j++)
      {
         intArray[j] = j;
         cout << "intArray[" << j << "] okay..." << endl;
      }
   }
   catch (xBoundary)
   {
      cout << "Unable to process your input!" << endl;
   }
   catch (Array<int>::xSize)
   {
      cout << "Bad Size!" << endl;
   }

   cout << "Done." << endl;
   return 0;
}