#include <iostream>
#include <stdio.h>

class base
{
  public:
  base()
  :baseName(""),baseData(0)
  {}
  
  base(std::string bn,int bd)
  :baseName(bn),baseData(bd)
  {}
  
  std::string getBaseName() const
  {
    return baseName;
  }
  
  int getBaseData()const
  {
    return baseData;
  }
  
  private:
    std::string baseName;
    int baseData;
};

class derived:public base
{
  public:
    derived():base(),derivedName("")
    {}
    derived(std::string bn,int bd,std::string dn)
    :base(bn,bd),derivedName(dn)
    {}
    std::string getDerivedName() const
    {
      return derivedName;
    }
  private:
    std::string derivedName;
};

void show(std::string& info,const base& b)
{
  info.append("Name is ");
  info.append(b.getBaseName());
  info.append(", baseData is ");
  char buffer[10];
  sprintf(buffer,"%d",b.getBaseData());
    info.append(buffer);
}

int main(int argc,char* argv[])
{
  base b("test",10);
  std::string s;
  show(s,b);
  std::cout<<s<<std::endl;
  derived d("btest",5,"dtest");
  std::string ss;
  show(ss,d);
  std::cout<<ss<<std::endl;
  return 0;
}

void show2(std::string& info,const derived& d)
{
  info.append("Name is ");
  info.append(d.getBaseName());
  info.append(", baseData is ");
  char buffer[10];
  sprintf(buffer,"%d",d.getBaseData());
  info.append(buffer);
}

1 derived_class.cpp: In function `int main(int, char**)':
2 derived_class.cpp:84: error: invalid initialization of reference of type 'const derived&' from expression of type 'base'
3 derived_class.cpp:70: error: in passing argument 2 of `void show2(std::string&, const derived&)'

class base
{
  public:
    std::string testPublic()
    {
      return std::string("this is public base");
    }
  protected:
    std::string testProtected()
    {
      return std::string("this is protected base");
    }
  private:
    std::string testPrivate()
    {
      return std::string("this is private base");
    }
};

class derivedPublic:public base
{
  public:
    std::string testPubPublic()
    {
      return testPublic()+= "in derived";
    }
    
    std::string testProPublic()
    {  
      return testProtected()+= "in derived";
    }
    
    std::string testPriPublic()          
    {  
      return testPrivate()+= "in derived";
    }
};

int main(int argc,char* argv[])
｛
  derivedPublic dpub;
  std::cout << dpub.testPublic() << std::endl; 
｝

derived11.cpp:16: error: `std::string base::testPrivate()' is private
derived11.cpp:36: error: within this context

#include <iostream>
#include <string>

class base
{
  public:
    std::string testPublic()
    {
      return std::string("this is public base");
    }
  protected:
    std::string testProtected()
    {
      return std::string("this is protected base");
    }
  private:
    std::string testPrivate()
    {
      return std::string("this is private base");
    }
};

class derivedPublic:public base
{
  public:
    std::string testPubPublic()
    {
      return testPublic()+= "in derived";
    }
    
    std::string testProPublic()
    {  
      return testProtected()+= "in derived";
    }
    
//    std::string testPriPublic()          
//    {  
//      return testPrivate()+= "in derived";
//    }
};

class deepDerived:public derivedPublic
{
  public:
    std::string deepProtected()
    {
      return testProtected() +="in deep";
    }
    
    std::string deepPublic()
    {
      return testPublic() +="indeep";
    }
};

int main(int argc,char* argv[])
{
  derivedPublic dpub;
  std::cout << dpub.testProtected() << std::endl; 
  deepDerived deepdpub;
  std::cout<<deepdpub.testPublic() <<std::endl;
  std::cout<<deepdpub.testProtected() <<std::endl;
  std::cout<<deepdpub.deepProtected() <<std::endl;
  std::cout<<deepdpub.deepPublic() <<std::endl;
}

derived12.cpp:13: error: `std::string base::testProtected()' is protected
derived12.cpp:62: error: within this context

#include <iostream>
#include <string>
class base
{
  public:
    std::string testPublic()
    {
      return std::string("this is public base");
    }
  protected:
    std::string testProtected()
    {
      return std::string("this is protected base");
    }
  private:
    std::string testPrivate()
    {
      return std::string("this is private base");
    }
};

class derivedPublic:public base
{
  public:
    std::string testPubPublic()
    {
      return testPublic()+= "in derived";
    }
    
    std::string testProPublic()
    {  
      return testProtected()+= "in derived";
    }
    
//    std::string testPriPublic()          //私有成员并没有被继承下来
//    {  
//      return testPrivate()+= "in derived";
//    }
};

class deepDerived:public derivedPublic
{
  public:
    std::string test()
    {
      return testPublic() +="in 3";
    }
};

class derivedProtected:protected base
{
  public:
    std::string testPubProtected()
    {
      return testPublic()+= "in derived";
    }
    
    std::string testProProtected()
    {  
      return testProtected()+= "in derived";
    }
};

class deepDerived2:public derivedProtected
{
  public:
    std::string test()
    {
      return testPublic() +="in 3";
    }
};

class derivedPrivate:private base
{
  public:
    std::string testPubPirvate()
    {
      return testPublic()+= "in derived";
    }
    
    std::string testProPrivate()
    {  
      return testProtected()+= "in derived";
    }
    
};

//class deepDerived3:public derivedPrivate
//{
//  public:
//    std::string test()
//    {
//      return testPublic() +="in 3";
//    }
//};

int main(int argc,char* argv[])
{
  derivedPublic dpub;
  //derivedProtected dpro;
  //derivedPrivate dpri;
  std::cout<<dpub.testPublic()<<std::endl;    //
  //std::cout<<dpub.testProtected()<<std::endl;  //用户被继承也是无法使用
  //cout<<dpub.testPrivate()<<std::endl;     //基类都是私有函数
  std::cout<<dpub.testPubPublic()<<std::endl;
  std::cout<<dpub.testProPublic()<<std::endl;
  //std::cout<<dpub.testPriPrivate()<<std::endl; //没有被继承
  
  deepDerived dd;
  std::cout<<dd.test()<<std::endl;
    
  derivedProtected dpro;
  //std::cout<<dpro.testPublic()<<std::endl;    //变成protected类型
  std::cout<<dpro.testPubProtected()<<std::endl;
  std::cout<<dpro.testProProtected()<<std::endl;
    
  deepDerived2 dd2;
  std::cout<<dd2.test()<<std::endl;
    
  derivedPrivate dpri;
  std::cout<<dpri.testPubPirvate()<<std::endl;
  std::cout<<dpri.testProPrivate()<<std::endl;
  
//  deepDerived3 dd3;
//  std::cout<<dd3.test()<<std::endl;
｝