symbol(s) not found for architecture x86_64 c++

Question

I am making a simple C++ program in Eclipse that makes a CastEmission and a LiveEmission object and fills in the information from a text file. When I compile it, this error occurs "symbol(s) not found for architecture x86_64".

#include<iostream>
#include<fstream>
#include<string>
#include<cstring>

using std::cin;
using std::cout;
using std::string;
using std::ifstream;

class Emission {
private:
    string title;
    string description;
    int idNumber;
    string tvProducer;
    string live;

    Emission* next;

 public:
     Emission(ifstream *myInput){
         char data[200];

         string idNumStr;

        myInput->getline(data, 200);
        idNumStr = strtok(data, "<>");
        idNumber= stoi(idNumStr, NULL, 10);
        title = strtok(NULL, "<>");
        description = strtok(NULL, "<>");
        tvProducer = strtok(NULL, "<>");
        live = strtok(NULL, "<>");

        next = NULL;
    }

    string GetTitle(){return title; }
    string GetDescription(){return description; }
    string GetTvProd(){ return tvProducer;}
    string GetLive(){ return live;}
    int GetId(){ return idNumber; }
    Emission* GetNext(){ return next;}

    void SetNext(Emission* temp){
    next = temp;
   }

    virtual void PrintEmissionEvents(){
    cout << ' ' << GetTitle() << ' ' << GetDescription()
            << ' ' <<GetTvProd() << ' ' << GetLive()
            << ' ' <<GetId() << " Emission\n";
    }
   virtual void PrintEmissionDetails() = 0;

   virtual ~Emission(){}
   //...
};

class LiveEmission : public Emission {
 private:
    //...

 public:
      LiveEmission(ifstream *myInput) : Emission(myInput){

  }

   virtual void PrintEmissionEvents(){

   }
    virtual void PrintEmissionDetails(){
    cout << ' ' << GetTitle() << ' ' << GetDescription()
            << ' ' <<GetTvProd() << ' ' << GetLive()
            << ' ' <<GetId() << " live\n";
     }
   //...
  };


 class CastEmission : public Emission {
 private:
   //...

 public:
  CastEmission(ifstream *myInput) : Emission(myInput){

   }

    virtual void PrintEmissionEvents();
    virtual void PrintEmissionDetails(){
        cout << ' ' << GetTitle() << ' ' << GetDescription()
            << ' ' <<GetTvProd() << ' ' << GetLive()
            << ' ' <<GetId() << " cast\n";
     }
    //...
 };


 int main(){
   ifstream myInputH("myIn.txt");
   ifstream *myInput = &myInputH;
    if(myInput->is_open()){
        CastEmission cast1(myInput);
        LiveEmission live2(myInput);

        cast1.PrintEmissionDetails();
        live2.PrintEmissionDetails();
    }
    else{
        cout << "Error! File could not be opened.\n";
    }

      myInput->close();

      return 0;
  }

This is the input file:

<1>< Sportcast><something something><J K Smith><cast>
<2><Athlitiki Kuriaki><Milaei kai i koutsi maria><Vasilis Bakopoulos><live>