I'm just trying to get a handle on the when and why of overloaded operators.
I the following snippet:
the line: T& operator[] ... is there for use in the copy constructor?
the line : const T& operator [] ... is there for the constructor definition?
In english, the code is instructing the compiler to return an array pointer of pType[] when encountering an array refernce from T.
this is what enables the program to be versatile by being able to select different array types to be displayed?
the line:
Array<T>& Array<T>::operator=(const Array &rhs)
is there to enable the seleted array to be passed into a template reference? Is this the only way to do it?
template <class T >
class Array;
template <class T>
ostream& operator << (ostream& , Array<T>& );
template <class T> //declare the template and the parameter
class Array // the class being paramterized
{
public:
//costrucyors
Array(int itsSize = DefaultSize);
Array(const Array &rhs);
~Array() {delete [] ptype;}
//operators
Array& operator = (const Array&);
T& operator [] (int offset) {return ptype[offset];}
const T& operator[] (int offset) const
{return ptype[offset];}
//accessors
int GetSize() const {return itsSize;}
friend ostream& operator << <> (ostream&, Array<T>&);
private :
T *ptype;
int itsSize;
};
template <class T >
ostream& operator << (ostream& output, Array<T>& theArray)
{
for (int i = 0; i < theArray.itsSize; i++)
output << "[" << i << "]" << theArray[i] <<endl;
return output;
}
//implementations follow...
//implement the constructor
template <class T>
Array<T>::Array(int size):
itsSize(size)
{
ptype = new T[size];
//the constructors of the type created
//should be of default value
}
//copy constructor
template <class T>
Array<T>::Array(const Array &rhs)
{
itsSize =rhs.GetSize();
ptype = new T[itsSize];
for (int i=0; i<itsSize; i++)
ptype[i] = rhs[i];
}
//operator=
template <class T>
Array<T>& Array<T>::operator=(const Array &rhs)
{
if (this == &rhs)
return *this;
delete [] ptype;
itsSize = rhs.GetSize();
ptype = new T[itsSize];
for (int i =0; i<itsSize; i++)
ptype[i] =rhs[i];
return *this;
}