In this chapter, the section Specialized Templates within section 16.4 describes how to design templates that are specialized for one particular data type. The section introduces a method for specializing a version of the SimpleVector class template so it will work with strings. Complete the specialization for both the SimpleVector and SearchableVector templates. Demonstrate them with a simple driver program.

See explaination for code

Explanation:

#ifndef SIMPLEVECTOR_H

#define SIMPLEVECTOR_H

#include <iostream>

#include <new> // Needed for bad_alloc exception

#include <cstdlib> // Needed for the exit function

using namespace std;

template <class T>

class SimpleVector

{

private:

T *aptr; // To point to the allocated array

int arraySize; // Number of elements in the array

void memError(); // Handles memory allocation errors

void subError(); // Handles subscripts out of range

public:

// Default constructor

SimpleVector()

{ aptr = 0; arraySize = 0;}

// Constructor declaration

SimpleVector(int);

// Copy constructor declaration

SimpleVector(const SimpleVector &);

// Destructor declaration

~SimpleVector();

// Accessor to return the array size

int size() const

{ return arraySize; }

// Accessor to return a specific element

T getElementAt(int position);

// Overloaded [] operator declaration

T &operator[](const int &);

};

//

// Constructor for SimpleVector class. Sets the size of the *

// array and allocates memory for it. *

//

template <class T>

SimpleVector<T>::SimpleVector(int s)

{

arraySize = s;

// Allocate memory for the array.

try

{

aptr = new T [s];

}

catch (bad_alloc)

{

memError();

}

// Initialize the array.

for (int count = 0; count < arraySize; count++)

*(aptr + count) = 0;

}

//

// Copy Constructor for SimpleVector class. *

//

template <class T>

SimpleVector<T>::SimpleVector(const SimpleVector &obj)

{

// Copy the array size.

arraySize = obj.arraySize;

// Allocate memory for the array.

aptr = new T [arraySize];

if (aptr == 0)

memError();

// Copy the elements of obj's array.

for(int count = 0; count < arraySize; count++)

*(aptr + count) = *(obj.aptr + count);

}

//

// Destructor for SimpleVector class. *

//

template <class T>

SimpleVector<T>::~SimpleVector()

{

if (arraySize > 0)

delete [] aptr;

}

//

// memError function. Displays an error message and *

// terminates the program when memory allocation fails. *

//

template <class T>

void SimpleVector<T>::memError()

{

cout << "ERROR:Cannot allocate memory.\n";

exit(EXIT_FAILURE);

}

//

// subError function. Displays an error message and *

// terminates the program when a subscript is out of range. *

//

template <class T>

void SimpleVector<T>::subError()

{

cout << "ERROR: Subscript out of range.\n";

exit(EXIT_FAILURE);

}

//

// getElementAt function. The argument is a subscript. *

// This function returns the value stored at the *

// subcript in the array. *

//

template <class T>

T SimpleVector<T>::getElementAt(int sub)

{

if (sub < 0 || sub >= arraySize)

subError();

return aptr[sub];

}

//

// Overloaded [] operator. The argument is a subscript. *

// This function returns a reference to the element *

// in the array indexed by the subscript. *

//

template <class T>

T &SimpleVector<T>::operator[](const int &sub)

{

if (sub < 0 || sub >= arraySize)

subError();

return aptr[sub];

}

template <class T>

class SearchableVector : public SimpleVector<T>{

public:

SearchableVector() : SimpleVector<T>(){};

SearchableVector(int a) : SimpleVector<T>(a){};

int findElement(T a){

for (int i = 0; i<SimpleVector<T>::size(); i++){

if (SimpleVector<T>::getElementAt(i) == a){

return i;

}

}

return -1;

}

};

int main(){

SimpleVector<int> s;

SimpleVector<int> s1(2);

SimpleVector<int> s3(20);

SimpleVector<int> s4(s3);

SearchableVector<int> s5(3);

cout << "Size:" << s.size() << endl;

cout << "Size:" << s1.size() << endl;

cout << "Size:" << s4.size() << endl;

s1[0] = 2;

s1[1] = 3;

s5[0] = 1;

s5[1] = 2;

s5[2] = 3;

cout << s1.getElementAt(0) << endl;

int a = s5.findElement(2);

if (a != -1)

cout << "Found at " << a << " postion\n";

else

cout << "Not Found\n";

return 0;

}

#endif