에러를 못잡겠습니다.

#ifndef BASE1_H
#define BASE1_H

class Base1
{
public :
	Base1( int parameterValue )
	{
		value = parameterValue;
	}

	int getData() const {	return value; }

protected :
	int value; // 파생 클래스에 의해 상속
};

#endif

#ifndef BASE2_H
#define BASE2_H

class Base2
{
public :
	Base2( char characterData )	{ letter = characterData; }
	char getData() const	{ return letter; }

protected :
	char letter; // 파생 클래스에 의해 상속
};

#endif

#ifndef DERIVED_H
#define DERIVED_H

#include <iostream>

using std::ostream;

#include "base1.h"
#include "base2.h"

class Derived : public Base1, public Base2
{
public :
	Derived( int, char, double  );
	double getReal() const;

private :
	double real;
};

#endif

#include "derived.h"

Derived::Derived( int integer, char character, double double1 )
	:Base1( integer ), Base2( character ), real( double1 )
{

}

double Derived::getReal() const { return real; }

ostream &operator << ( ostream &output, const Derived &derived )
{
	output << "		Integer: " <<   derived.value
		   << "\n   character: " << derived.letter
		   << "\nReal number: " <<  derived.real;

	return output;
}		

#include <iostream>

using std::cout;
using std::endl;

#include "base1.h"

#include "base2.h"
#include "derived.h"

int main ( void )
{
	Base1 base1( 10 ), *base1Ptr  = 0;
	Base2 base2( 'Z' ), *base2Ptr = 0;

	Derived derived( 7, 'A', 3.5  );

	cout << "object base1 contains integer "
		<< base1.getData()
		<< "\nObject base2 contains character "
		<< "\nObject derived contains: \n" << derived << "\n\n";

	cout << "Data members of Derived can be"
		<< "accessed individually: "
		<< "\n		Integer: " << derived.Base1::getData()
		<< "\n	Character  : " << derived.Base2::getData()
		<< "\nReal number  : " << derived.getReal() << "\n\n";

	cout << "Derived can be breated as an "
		<< "object of either base class: \n";

	base1Ptr = &derived;
	cout << "base1Ptr->getData() yields "
		<< base1Ptr->getData() << '\n';

	base2Ptr = &derived;
	cout << "base2Ptr->getData() yields "
		<< base2Ptr->getData() << endl;

	return 0;
}

에러무작위로 쏟아 집니다.

fig.cpp: In function `int main()':
fig.cpp:21: no match for `std::basic_ostream<char, std::char_traits<char> >& <<
   Derived&' operator
/usr/include/c++/3.2.2/bits/ostream.tcc:55: candidates are:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(std::basic_ostream<_CharT,
   _Traits>&(*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char,
   _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:77:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(std::basic_ios<_CharT,
   _Traits>&(*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits
   = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:99:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(std::ios_base&(*)(std::ios_base&)) [with _CharT = char,
   _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:171:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(long int) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:208:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(long unsigned int) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:146:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(bool) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:104:                 std::basic_ostream<_CharT,
   _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with
   _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:115:                 std::basic_ostream<_CharT,
   _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned
   int) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:119:                 std::basic_ostream<_CharT,
   _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT
   = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:130:                 std::basic_ostream<_CharT,
   _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int)
   [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:234:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(long long int) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:272:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(long long unsigned int) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:298:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(double) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:145:                 std::basic_ostream<_CharT,
   _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with
   _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:323:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(long double) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:348:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(const void*) [with _CharT = char, _Traits =
   std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:120:
   std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT,
   _Traits>::operator<<(std::basic_streambuf<_CharT, _Traits>*) [with _CharT =
   char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:251:                 std::basic_ostream<char,
   _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned
   char*) [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:246:                 std::basic_ostream<char,
   _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const signed
   char*) [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:622:
   std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char,
   _Traits>&, const char*) [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:572:
   std::basic_ostream<_CharT, _Traits>&
   std::operator<<(std::basic_ostream<_CharT, _Traits>&, const char*) [with
   _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:227:                 std::basic_ostream<char,
   _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char)
   [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:222:                 std::basic_ostream<char,
   _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, signed char)
   [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/bits/ostream.tcc:500:
   std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char,
   _Traits>&, char) [with _Traits = std::char_traits<char>]
/usr/include/c++/3.2.2/ostream:211:                 std::basic_ostream<_CharT,
   _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char) [with
   _CharT = char, _Traits = std::char_traits<char>]
fig.cpp:14: warning: unused variable `Base2 base2'
base1.h: In function `std::ostream& operator<<(std::ostream&, const Derived&)':
base1.h:15: `int Base1::value' is protected
derived.cpp:14: within this context
base2.h:11: `char Base2::letter' is protected
derived.cpp:15: within this context
derived.h:18: `double Derived::real' is private
derived.cpp:15: within this context

지금 책 예제 따라 하면서 공부하고 있는데...무작위로 쏟아 집니다.^^;