Compiler Fejl ved abstrakte klasser

[Allan Nielsen <sslug@sslug>]

Hej

Jeg er gået i gang med at programmer et program som i første omgang skal 
kunne tolke en string bestående af et matematisk udtryk, og retuner det 
beregnet tal, f.eks 2*3+4 = 10.
Til at gøre dette har jeg lavet følgende klasser heraki:
Operator som er den øverste klasse, og som er erklaret abstrakt,
Operator1, Operator2, Operator3, Operator4  ... som arver fra Operater 
klassen, disse er også abstrakte klasser.
Tilsidst er der de matematiske operator, plus, minus, gange, osv,  som 
arver fra Operator2 pågrund af at de tager 2 arkumenter.
sin(), ln(), sqrt() , osv. arver fra Operator1 da de kun tager 1 argument.
Operator0, er normale tal.

compiler siger følgende:
f1(Operator*, Operator*)':
*/home/allan/Projects/cpp/stringmath2/src/stringmath2.cpp:19: error: 
`Operator' is an inaccessible base of `Oplus'
*/home/allan/Projects/cpp/stringmath2/src/stringmath2.cpp: I function 
'Operator* 
*f2(Operator*, Operator*)':
*/home/allan/Projects/cpp/stringmath2/src/stringmath2.cpp:24: error: 
`Operator' is an inaccessible base of `Ominus'
*/home/allan/Projects/cpp/stringmath2/src/stringmath2.cpp: I function 'int 
*main(int, char**)':
*/home/allan/Projects/cpp/stringmath2/src/stringmath2.cpp:40: error: 
`Operator' is an inaccessible base of `Operator0'
*make[2]: *** [stringmath2.o] Fejl 1

den tilførende kode ser således ud (dette er main metoden, og jeg ved 
godt at det jeg laver ikke er optimal, men det giver menig når det 
bliver færdig!)

(dette er bare den udsnit som jeg mener fejlen ligger i, hele koden er 
ved hæftte)

18   Operator* f1(Operator* s1,Operator* s2){
19      Operator* o = new Oplus(s1, s2, '\0');
20      return o;
21   }
22  
23   Operator* f2(Operator* s1,Operator* s2){
24      Operator* o = new Ominus(s1, s2,'\0');
25      return o;
26   }

.....

32   int returVeardi = 0;
33   Operator0* s1 = new Operator0(2, 0);
34   Operator0* s2 = new Operator0(5, 0);
35
36   Operator * ( * fun_array[2])(Operator* , Operator*) = {f1, f2};
37
38   fun_array[returVeardi](s1, s2);

MVH
Allan Nielsen

PS
Jeg er stadig ny begybder til cpp, så i må bære over med mig hvis jeg 
stiller dumme spørgsmål

bin_PROGRAMS = stringmath2
stringmath2_SOURCES = stringmath2.cpp operator.cpp operator2.cpp oplus.cpp ominus.cpp operator0.cpp

# set the include path found by configure
INCLUDES= $(all_includes)

# the library search path.
stringmath2_LDFLAGS = $(all_libraries) 
noinst_HEADERS = operator.h operator2.h oplus.h ominus.h operator0.h

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# Copyright (C) 1994, 1995-8, 1999, 2001 Free Software Foundation, Inc.
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bin_PROGRAMS = stringmath2
stringmath2_SOURCES = stringmath2.cpp operator.cpp operator2.cpp oplus.cpp ominus.cpp operator0.cpp

# set the include path found by configure
INCLUDES = $(all_includes)

# the library search path.
stringmath2_LDFLAGS = $(all_libraries) 
noinst_HEADERS = operator.h operator2.h oplus.h ominus.h operator0.h
mkinstalldirs = $(SHELL) $(top_srcdir)/mkinstalldirs
CONFIG_HEADER = ../config.h
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bin_PROGRAMS =  stringmath2$(EXEEXT)
PROGRAMS =  $(bin_PROGRAMS)


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CPPFLAGS = @CPPFLAGS@
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operator2.$(OBJEXT) oplus.$(OBJEXT) ominus.$(OBJEXT) \
operator0.$(OBJEXT)
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.deps/operator2.P .deps/oplus.P .deps/stringmath2.P
SOURCES = $(stringmath2_SOURCES)
OBJECTS = $(stringmath2_OBJECTS)

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# Tell versions [3.59,3.63) of GNU make to not export all variables.
# Otherwise a system limit (for SysV at least) may be exceeded.
.NOEXPORT:

#include "ominus.h"

Ominus::Ominus(Operator* child1, Operator* child2, Operator* parent) : Operator2(child1, child2, parent, "+")
{
}

double Ominus::getDouble()
{
    return child1->getDouble() + child1->getDouble();
}

std::string Ominus::getSymbol(){
     return symbol;
}

Ominus::~Ominus()
{
}

#ifndef OMINUS_H
#define OMINUS_H

#include <string>

#include "operator.h"
#include "operator2.h"


/**
@author Allan W. Nielsen
*/
class Ominus : Operator2{
public:
    Ominus(Operator* child1, Operator* child2, Operator* parent);
    double getDouble();
    std::string getSymbol();
    
    ~Ominus();

};

#endif

#include "operator.h"

Operator::Operator(Operator* parent, int iNumberOfArg)
{
        this->iNumberOfArg = iNumberOfArg;
}


Operator::~Operator()
{
}

#ifndef OPERATOR_H
#define OPERATOR_H

/**
@author Allan W. Nielsen
*/
class Operator{
public:
    Operator* parent;
    int iNumberOfArg;

    Operator(Operator* parent, int iNumberOfArg);

    virtual double getDouble() = 0;

    
    ~Operator();

};

#endif


#include "operator0.h"


Operator0::Operator0(int i, Operator* parent) : Operator(parent, 0)
{
    this->i = i;
}

double Operator0::getDouble(){
return (double) i;
}

Operator0::~Operator0()
{
}


#ifndef OPERATOR0_H
#define OPERATOR0_H
#include "operator.h"

/**
@author Allan W. Nielsen
*/
class Operator0 : Operator{
public:
    int i;

    Operator0(int i, Operator * parent);
    
    double getDouble();

    ~Operator0();

};

#endif

#include "operator2.h"

Operator2::Operator2(Operator* child1, Operator* child2, Operator* parent, std::string symbol) : Operator(parent, 2)
{
    this->child1 = child1;
    this->child2 = child2;
    this->symbol = symbol;
}


Operator2::~Operator2()
{
}

#ifndef OPERATOR2_H
#define OPERATOR2_H

#include <string>
#include "operator.h"

/**
@author Allan W. Nielsen
*/
class Operator2 : public Operator {
public:

    Operator* child1;
    Operator* child2;
    std::string symbol;
    
    Operator2(Operator* child1, Operator* child2, Operator* parent, std::string symbol);
    
    virtual std::string getSymbol() = 0;

    ~Operator2();

};

#endif

#include "oplus.h"

Oplus::Oplus(Operator* child1, Operator* child2, Operator* parent) : Operator2(child1, child2, parent, "+")
{
}

double Oplus::getDouble()
{
    return child1->getDouble() + child1->getDouble();
}

std::string Oplus::getSymbol(){
     return symbol;
}

Oplus::~Oplus()
{
}


#ifndef OPLUS_H
#define OPLUS_H

#include <string>

#include "operator.h"
#include "operator2.h"


/**
@author Allan W. Nielsen
*/
class Oplus : Operator2{
public:
    Oplus(Operator* child1, Operator* child2, Operator* parent);
    double getDouble();
    std::string getSymbol();
    
    ~Oplus();

};

#endif

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream>
#include <cstdlib>

#include "oplus.h"
#include "operator0.h"
#include "operator.h"
#include "ominus.h"

//sslug@sslug

using namespace std;

Operator* f1(Operator* s1,Operator* s2){
  Operator* o = new Oplus(s1, s2, '\0');
  return o;
}

Operator* f2(Operator* s1,Operator* s2){
  Operator* o = new Ominus(s1, s2,'\0');
  return o;
}

int main(int argc, char *argv[])
{
  cout << "Hello, world!" << endl;

  int returVeardi = 0;
  
  
  Operator0* s1 = new Operator0(2, 0);
  Operator0* s2 = new Operator0(5, 0);
  
  Operator * ( * fun_array[2])(Operator* , Operator*) = {f1, f2};
  
  fun_array[returVeardi](s1, s2);
  
  return 0;  
}