* στο οποίο εφαρμόζεται.

Προκειμένου να μπορέσουμε να παρακολουθήσουμε την υπερφόρτωση των τελεστών υπερφορτώνουμε τον τελεστή =. Η επεξήγηση της υπερφόρτωσης του τελεστή = θα δοθεί στη συνέχεια.

Vector operator++();
Vector operator--();

Vector operator++(int a);
Vector operator--(int a);

Vector.cpp

#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;
 
class Vector {
  int *array;
  unsigned int size;
 
public:
  Vector(unsigned int length=0);
  Vector(const Vector &v);
  Vector(const Vector *v);
  ~Vector();
  unsigned int length() const;           // return Vector's length.
  int &valueAt(unsigned int pos) const;  // return a reference to element at position pos
  int find(int a) const;      // check if a exists in Vector. Return it position >0 or -1 
                              // if not element not found
 
  void print() const;           // print vector values to standard output
  void print(string &msg) const;  // print vector values to standard output
  void operator=(const Vector &v);
 
  int operator+() const;     // returns the sum of all elements
  Vector operator-() const;  // returns a new Vector with negative values;
  Vector operator++();       // prefix increment
  Vector operator--();       // prefix decrement
  int operator*() const;     // returns the product of Vector elements
  Vector operator~() const;  // returns the binary NOT for each element in a new Vector
  friend Vector operator!(const Vector &v);  // returns a new Vector with inverted sequence of elements
 
  Vector operator++(int );   // postfix increment
  Vector operator--(int );   // postfix decrement
};
 
Vector::Vector(unsigned int length) {
  size = length;
  array = new (nothrow) int[size];
  if(array==NULL) {
    cerr << "Memory allocation failure!" << endl;
    exit(-1);
  }
  for(int i=0; i<size; i++)
    array[i] = 0;
}
 
Vector::Vector(const Vector &v) {
  size = v.length();
  array = new (nothrow) int[size];
  if(array==NULL) {
    cerr << "Memory allocation failure!" << endl;
    exit(-1);
  }
  for(int i=0; i<size; i++)
    array[i] = v.valueAt(i);
}
 
Vector::Vector(const Vector *v) {
  size = v->length();
  array = new (nothrow) int[size];
  if(array==NULL) {
    cerr << "Memory allocation failure!" << endl;
    exit(-1);
  }
  for(int i=0; i<size; i++)
    array[i] = v->valueAt(i);
}
 
Vector::~Vector() {
  delete [] array;
}
 
unsigned int Vector::length() const { 
  return size; 
}
 
int &Vector::valueAt(unsigned int pos) const {
  if(pos>=length()) {
     cerr << "Invalid access position!\n";
     return array[size-1];
  }
  return array[pos];
}
 
int Vector::find(int a) const {
  for(int i=0; i<size; i++)
    if(array[i] == a)
      return i;
    return -1;
}
 
void Vector::print() const {
  for(int i=0; i<size; i++) {
    cout << array[i];
    if(i==size-1)
      cout << endl;
    else
      cout << ", ";
  }
}
 
void Vector::print(string &msg) const {
  cout << msg;
  for(int i=0; i<size; i++) {
    cout << array[i];
    if(i==size-1)
      cout << endl;
    else
      cout << ", ";
  }
}
 
void Vector::operator=(const Vector &v) {
  if(array!=NULL)
    delete [] array;
  size = v.length();
  array = new (nothrow) int[size];
  if(array==NULL) {
    cerr << "Memory allocation failure!" << endl;
    exit(-1);
  }
  for(int i=0; i<size; i++)
    array[i] = v.valueAt(i);  
}
 
int Vector::operator+() const{
  int sum=0.0;
  for(int i=0; i<size; i++) {
    sum += array[i];
  }
  return sum;
}
 
Vector Vector::operator-() const{
  Vector v(size);
  for(int i=0; i<size; i++) {
    v.valueAt(i) = -array[i];
  }
  return v;
}
 
//prefix increment
Vector Vector::operator++() {
  for(int i=0; i<size; i++) {
    array[i]++;
  }
  Vector v(this);
  return v;
}
//prefix decrement
Vector Vector::operator--() {  
  for(int i=0; i<size; i++) {
    array[i]--;
  }
  Vector v(this);
  return v;
}
 
int Vector::operator*() const{
  int product = 1;
  for(int i=0; i<size; i++)
    product *= array[i];
  return product;
}
 
Vector Vector::operator~() const{
  Vector v(size);
  for(int i=0; i<size; i++)
    v.valueAt(i) = ~array[i];
  return v;
}
 
Vector operator!(const Vector &v) {
  Vector n = v;
  for(int i=0; i<v.size; i++)
    n.array[i] = v.array[v.size-1-i];
  return n;
}
 
//postfix increment
Vector Vector::operator++(int a) {
  Vector v(this);
  for(int i=0; i<size; i++) {
    array[i]++;
  }  
  return v;
}
 
//postfix decrement
Vector Vector::operator--(int a) {
  Vector v(this);
  for(int i=0; i<size; i++) {
    array[i]--;
  }  
  return v;
}
 
 
int main() {
  Vector v(5);
  v.valueAt(0) = 2;  v.valueAt(1) = 3;
  v.valueAt(2) = 4;  v.valueAt(3) = 5;  v.valueAt(4) = 6;
 
  string msg = "Initial Vector: ";
 
  v.print(msg);
  int sum = +v;
  cout << "Sum of elements: " << sum << endl;
 
  Vector f = -v;
  f.print(msg="Negative values: ");
  int product = *v;
  cout << "Product of elements: " << product << endl;
 
  f = !v;
  f.print(msg = "Inverted sequence: ");
 
  f = ~v;
  f.print(msg = "Binary inverted: ");
 
  msg = "-------------\nPrefix increment";
  cout << msg << endl;
  f = ++v;
  v.print(msg = "Initial Vector: ");
  f.print(msg = "Assigned Vector: ");
 
  msg = "-------------\nPostfix decrement";
  cout << msg << endl;
  f = v--;
  v.print(msg = "Initial Vector: ");
  f.print(msg = "Assigned Vector: ");
}