C / C++ / MFC

class DirectoryTreeWalker
{
   DirectoryTreeWalker(std::string& path) { … }
   void WalkIt() { // Go through the directory tree, call FoundAFile when you see a file, FoundADirectory for a directory }
private:
   virtual void FoundAFile(const std::string& file) = 0;
   virtual void FoundADirectory(const std::string& file) = 0;
};

hrishiS wrote:

But there is always a small difference between the abstract class and interface.

hrishiS wrote:

Anyway, when we talk about interface also, when do we need/use them exactly?Could you please give me a practical example.

class CLogger
{
public:
   void LogMessage(const string& message)
   {
      string formattedMessage = FormatMessage(message);
      OutputMessage(formattedMessage);
   }

protected:
   string FormatMessage(const string& message) { /* Formats the message properly and returns it */ }
   virtual void OutputMessage(const string& message) = 0;

};

class CConsoleLogger : public CLogger
{
protected:
   void OutputMessage(const string& message) { /* Output the message to the console */ }
};

#include<iostream>

class IDumpable
{
public :
  virtual void  dump()=0;
};


class A: public IDumpable
{
  int _a;
public:
  A(int a):_a(a){}
  virtual void dump(){ std::cout << _a << std::endl;}
};

class B: public IDumpable
{
  static int _counter;
  double _d;
  int _id;
public:
  B(double d):_d(d){_id=B::_counter++;} 
  virtual void dump(){ std::cout << "(" << _id << ") " << _d << std::endl;}
};


int B::_counter=0;


void dump( IDumpable * pid[], int size)
{
  int i;
  for (i=0; i<size; i++)
  {
     pid[i]->dump();
  }
}

void main()
{
  IDumpable *pid[3];
  pid[0] = new A(10);
  pid[1] = new B(5.7);
  pid[2] = new B(10.745);
  dump(pid, sizeof(pid)/sizeof(pid[0]));
}

Kushagra Tiwari wrote:

and If they know it ..we should also be able to device the same

fley_fly wrote:

typedef boost::function1< void, std::vector<std::string>& > funcHolder

typedef boost::function< void(std::vector<std::string>&)> funcHolder; 

fley_fly wrote:

addCommand("clear", boost::bind(&Console::clear, this);

fley_fly wrote:

void Console::addCommand(const String &command, funcHolder f)