Temporary Object Management through Dual Classes

Listing 3 Vector and TempVector with dynamic VES

class TempVector;
class Vector             // Vector class definition
{    unsigned lng;            // Vector Length
    double *ves;             // Vector Element Space
public:
    friend TempVector;
    Vector ()                     // Default Constructor
    {    lng = 0;                 // No VES
        ves = NULL; }
    Vector (const unsigned ln)    // New Vector Constructor
    {    lng = ln;                // Set length
        ves = new double [ln]; } // Create new VES
    Vector (const Vector& v) // Copy Constructor
    {    lng = v.lng;             // Set length
        ves = new double [lng];       // Create new VES
        memcpy (ves, v.ves, lng * sizeof(double)); }
    Vector (TempVector&);         // Typecast "Copy" Constructor
    ~Vector () { if (ves != NULL) delete ves; } // Destructor
    double& operator()(const int coordinate) const
    {    // Address elements by coordinate
        return ves[coordinate]; }
    unsigned length() const { return lng; } // Report Vector length
    Vector& operator= (const Vector& v);    // Assignment operator
    Vector& operator= (TempVector& v);      // Assignement operator
    TempVector operator+ (const Vector&) const;  // Vector Addition
    TempVector operator+ (const TempVector&) const;   // Vector Addition
    friend TempVector unit (const Vector&); // Unitize Vector
};
class TempVector              // Temporary Vector class definition
{    unsigned lng;            // Vector Length
    double *ves;             // Vector Element Space
  friend Vector;
    TempVector ()            // Default Constructor
    {    lng = 0;                 // No VES
        ves = NULL; }
    TempVector (const unsigned ln) // New TempVector Constructor
    {    lng = ln;                // Set length
        ves = new double [ln]; } // Allocate new VES
    TempVector (TempVector& v)    // Copy Constructor
    {    lng = v.lng;             // Set length
        ves = v.ves;             // Seize VES
        v.ves = NULL; }
    unsigned length() const { return lng; } // Report Vector length
  public:
    ~TempVector () { if (ves != NULL) delete ves; } // Destructor
    double& operator()(const int coordinate) const
    {    // Address elements by coordinate
        return ves[coordinate]; }
    friend TempVector unit (const Vector&) // Unitize Vector
    friend TempVector unit (const TempVector&); // Unitize Vector
    // No assignment operator
    friend Vector::Vector (TempVector&);
    TempVector operator+ (const Vector&) const; // Vector Addition
    TempVector operator+ (const TempVector&) const; // Vector Addition
    friend TempVector Vector::operator+ (const TempVector&);
};
Vector::Vector (TempVector& v)
{    // Typecast "Copy" Constructor from TempVector to Vector
    ves = v.ves;             // Seize VES
    v.ves = NULL;
    lng = v.lng; }           // Set Vector length

Vector& Vector::operator= (const Vector& v)
{    // Assignment operator
    if (ves != v.ves) {      // Protect against self-reference
        if (ves != NULL) delete ves;  // Delete VES, if any
        lng = v.lng;             // Set Vector length
        ves = new double [lng];       // Allocate new VES & copy
        memcpy (ves, v.ves, lng * sizeof(double)); }
    return *this; }
Vector& Vector::operator= (TempVector& v)
{    // Assignment operator
    // No danger of self-reference
    if (ves != NULL) delete ves;  // Delete VES, if any
    lng = v.lng;             // Set Vector length
    ves = v.ves;             // Seize VES
    v.ves = NULL;
    return *this; }
TempVector Vector::operator+ (const Vector& v) const
{    // Vector addition
    if (v.lng != lng) exit(1);    // Ensure conformal addition
    TempVector u (lng);      // Create same size Vector
    for (int i = 0; i < lng; i++) // Carry out addition
        u.ves[i] = ves[i] + v.ves[i];
    return u; }
TempVector Vector::operator+ (const TempVector& v) const
{    // Vector addition
    if (v.lng != lng) exit(1);    // Ensure conformal addition
    TempVector u (lng);      // Create same size Vector
    for (int i = 0; i < lng; i++) // Carry out addition
        u.ves[i] = ves[i] + v.ves[i];
    return u; }
TempVector TempVector::operator+ (const Vector& v) const
{    // Vector addition
    if (v.lng != lng) exit(1);    // Ensure conformal addition
    TempVector u (lng);      // Create same size Vector
    for (int i = 0; i < lng; i++) // Carry out addition
        u.ves[i] = ves[i] + v.ves[i];
    return u; }
TempVector TempVector::operator+ (const TempVector& v) const
{    // Vector addition
    if (v.lng != lng) exit(1);    // Ensure conformal addition
    TempVector u (lng);      // Create same size Vector
    for (int i = 0; i < lng; i++) // Carry out addition
        u.ves[i] = ves[i] + v.ves[i];
    return u; }
// End of File