Перегрузка потокового оператора (<<). Выдает адрес вместо значения

@Leeto · Регистрация: 23.12.2011

Студворк — интернет-сервис помощи студентам

Сабж. Все компелится нормально. Если делать << void то работает ок см комменты
если делать класса std::ostream& то возвращает 16чное значение.
Заранее спасибо

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#ifndef Point_HPP // anti multiply including gates
#define Point_HPP
 
#include <sstream>
    
 
class Point
{   
    private:        //  declaration of private data members 
    double x;       // X coordinate
    double y;       // Y coordinate
 
    public: // public declaration of data members (in given example haven't ) and member functions 
 
 
        //----------- Declaration of Constructors -----------//
    Point();                                    // Default constructor
    Point(double newX, double newY);            // Constructor 
    Point (const Point& ObjectOfClassPoint);    //COPY constructor
    ~Point(); // 
 
 
    //----------- Declaration of  Accessors member functions -----------//
 
    std::ostream& ToString() ; 
    //void Point::ToString () const; 
    
    
};
 
 
//----------- Implementaion of Global Ostream << Operator  -----------//
 
/*std::ostream& operator<< (std::ostream &out, Point &cPoint) 
{
    // SHOULD BE WITHOUT friendness 
    // Point's members directly.
    out << cPoint.ToString();
        
    return out;
}*/
 
#endif // Point_HPP

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#include <iostream>
#include "Point.hpp"
 
 
 
 
int main()
 
    {
 
 
    std::cout << "\n\t ---TEST OF Operator Overloading--- \n";
    
    Point MyPoint(1455  , 1492  );                          // Creating an object of  Point using constructor 
    Point MySecondPoint (1517   , 1796  );                  // Creating an object of  Point using constructor 
    Point MyThirdPoint (1610  , 1882   );                   // Creating an object of  Point using constructor 
    MyPoint.ToString();
    MySecondPoint.ToString();
    std::cout << "\n";
 
 
    std::cout << "\n std::cout << MySecondPoint.ToString();;\n\n\n ";
    std::cout << "\n" <<  MySecondPoint.ToString();
 
 
    std::cout << "\n ---  Now some easy math --- ";
    
 
  return 0 ; 
}

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#include "Point.hpp"
#include <iostream>
#include <sstream>
#include <cmath>
 
 
 
 
 
            //----------- Implementation of Constructors -----------//
 
Point::Point() : x(0), y(0)                                                         // Default constructor (implemented using colon syntax )
{ 
    std::cout << "hi my default constructor\n\n\t";
}                                       
Point::Point(double newX, double newY) : x(newX), y(newY)                           // Constructor 
{ 
    //std::cout << "hi my constructor\n\n\t"; 
}               
Point::~Point()                                                                     // Destructor
{
    //std::cout << "bye my point..\n";
}                                    
 
Point::Point (const Point& ObjectOfClassPoint)                                      // Copy constructor
        {
            //std::cout << "this is COPY constructor\n\n\t ";
            x = ObjectOfClassPoint.x;
            y = ObjectOfClassPoint.y;
 
        }
 
 
        
 
            //----------- Implementation of Accessor(s) member functions -----------//
 
std::ostream& Point::ToString ()
    
    {// Function ToString should also be const also because of reason of mistaken modification of an object's value 
        std::ostringstream os;                              // std::stringstream object
        os << " Point (" << x << ", " << y << ")\n";            // customization of output 
        os.str();                                           // str() function retrieve the string from the string buffer
        return os;
 
    }
 
 
/*void Point::ToString () const
    
    {// Function ToString should also be const also because of reason of mistaken modification of an object's value 
        std::ostringstream os;                              // std::stringstream object
        os << " Point (" << x << ", " << y << ")";          // customization of output 
        std::cout << os.str()<<"\n";                        // str() function retrieve the string from the string buffer
    }
    */

Jupiter · 26.07.2012, 14:11

Сообщение от Leeto

std::ostream& Point::ToString ()
{// Function ToString should also be const also because of reason of mistaken modification of an object's value
std::ostringstream os; // std::stringstream object
os << " Point (" << x << ", " << y << ")\n"; // customization of output
os.str(); // str() function retrieve the string from the string buffer
return os;
}

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std::string Point::ToString ()
{// Function ToString should also be const also because of reason of mistaken modification of an object's value 
    std::ostringstream os;                        // std::stringstream object
    os << "Point (" << x << ", " << y << ")"; // customization of output 
    return os.str();                                  // str() function retrieve the string from the string buffer
}

Добавлено через 1 минуту

Сообщение от Leeto

std::ostream& operator<< (std::ostream &out, Point &cPoint)

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std::ostream& operator << (std::ostream &out, Point const& cPoint)

@Leeto · 26.07.2012, 14:21 **[ТС]**

Сообщение от Jupiter

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std::string Point::ToString ()
{// Function ToString should also be const also because of reason of mistaken modification of an object's value 
    std::ostringstream os;                        // std::stringstream object
    os << "Point (" << x << ", " << y << ")"; // customization of output 
    return os.str();                                  // str() function retrieve the string from the string buffer
}

Добавлено через 1 минуту

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std::ostream& operator << (std::ostream &out, Point const& cPoint)

А как мне теперь сделать так чтобы сразу можно было объект MySecondPoint послать на cout <<
Компилятор выдает Link error

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std::ostream& operator<< (std::ostream &out, Point &cPoint) 
{
    // SHOULD BE WITHOUT friendness 
    // Point's members directly.
 
    out << cPoint.ToString();
        
    return out;
}

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#include <iostream>
#include "Point.hpp"
 
 
 
 
int main()
 
    {
 
 
    std::cout << "\n\t ---TEST OF Operator Overloading--- \n";
    
    Point MyPoint(1455  , 1492  );                          // Creating an object of  Point using constructor 
    Point MySecondPoint (1517   , 1796  );                  // Creating an object of  Point using constructor 
    Point MyThirdPoint (1610  , 1882   );                   // Creating an object of  Point using constructor 
    MyPoint.ToString();
    MySecondPoint.ToString();
    std::cout << "\n";
 
 
    std::cout << "\n std::cout << MySecondPoint.ToString();;\n\n\n ";
    std::cout << "\n" <<  MySecondPoint.ToString();
 
 
    std::cout << "\n ---  Now some easy math --- ";
 
    std::cout << "\n MySecondPoint;\n\n\n ";
    std::cout << MySecondPoint;
    
 
  return 0 ; 
}

PS В этом задании нельзя френдить и надо использовать ToString() и надо чтобы operator << be Global но реализован внутри hpp

1>Point.obj : error LNK2005: "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class Point &)" (??6@YAAAV?$basic_ostream@DU?$char_trait s@D@std@@@std@@AAV01@AAVPoint@@@Z) already defined in main.obj

fatal error LNK1169: one or more multiply defined symbols found

Jupiter · 26.07.2012, 14:54

point.hpp

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#ifndef Point_HPP // anti multiply including gates
#define Point_HPP
 
#include <ostream>
#include <string>
    
class Point
{   
private:        //  declaration of private data members 
    double x;       // X coordinate
    double y;       // Y coordinate
 
public: // public declaration of data members (in given example haven't ) and member functions 
 
        //----------- Declaration of Constructors -----------//
    Point();                                    // Default constructor
    Point(double newX, double newY);            // Constructor 
    Point (const Point& ObjectOfClassPoint);    //COPY constructor
    ~Point(); // 
 
    //----------- Declaration of  Accessors member functions -----------//
    std::string ToString() const;    
};
 
 
//----------- Declaration of Global Ostream << Operator  -----------//
 
std::ostream& operator<< (std::ostream& out, Point const& cPoint); 
 
#endif // Point_HPP

Добавлено через 19 секунд

point.cpp

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#include "Point.hpp"
 
#include <iostream>
#include <sstream>
#include <cmath> 
  
            //----------- Implementation of Constructors -----------//
 
Point::Point() : x(0), y(0)                                                         // Default constructor (implemented using colon syntax )
{ 
    std::cout << "hi my default constructor\n\n\t";
}     
 
Point::Point(double newX, double newY) : x(newX), y(newY)                           // Constructor 
{ 
    //std::cout << "hi my constructor\n\n\t"; 
}
 
Point::~Point()                                                                     // Destructor
{
    //std::cout << "bye my point..\n";
}                                    
 
Point::Point (const Point& ObjectOfClassPoint)                                      // Copy constructor
{
    //std::cout << "this is COPY constructor\n\n\t ";
    x = ObjectOfClassPoint.x;
    y = ObjectOfClassPoint.y;
}
 
            //----------- Implementation of Accessor(s) member functions -----------//
 
std::string Point::ToString() const
{
    // Function ToString should also be const also because of reason of mistaken modification of an object's value 
    std::ostringstream os;                              // std::stringstream object
    os << " Point (" << x << ", " << y << ")\n";        // customization of output 
    return os.str();                                    // str() function retrieve the string from the string buffer
}
 
std::ostream& operator << (std::ostream& out, Point const& cPoint)
{
    // SHOULD BE WITHOUT friendness 
    // Point's members directly.
    return (out << cPoint.ToString());
}

Добавлено через 20 секунд

main.cpp

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#include <iostream>
#include "Point.hpp"
 
int main()
{
    std::cout << "\n\t ---TEST OF Operator Overloading--- \n";
    
    Point MyPoint(1455, 1492);                          // Creating an object of  Point using constructor 
    Point MySecondPoint (1517, 1796);                  // Creating an object of  Point using constructor 
    Point MyThirdPoint (1610, 1882);                   // Creating an object of  Point using constructor 
    
    std::cout << MyPoint << std::endl
        << MySecondPoint << std::endl
        << MyThirdPoint  << std::endl;
 
  return 0 ; 
}

@Leeto · 26.07.2012, 15:38 **[ТС]**