Unable to find segmentation fault error in c++ -

i have 3 c++ files, instrument.h, percussion.h, , instrumentapp.cpp. instrument.h base class , percussion.h inherits it. percussion objects defined , implemented in instrumentapp.cpp class. whenever run instrumentapp.cpp, segmentation fault error.

i have managed trace cause of error overloaded << operator function in percussion.h calling method of base class instrument.h. reason, code unable call methods of base class , don't know why. can please me?

here instrument.h class

#ifndef instrument_h #define instrument_h   class instrument{         private:                 std::string name;                 std::string sound;                 std::string lowrange;                 std::string highrange;         public:                 instrument(std::string name, std::string sound, std::string lowrange, std::string highrange){                         this->name = name;                         this->sound = sound;                         this->lowrange = lowrange;                         this->highrange = highrange;                 }                  std::string getname() const{                         return this->name;                 }                  std::string play()const {                         return this->sound;                 }                  std::string getlowrange() const{                         return this->lowrange;                 }                  std::string gethighrange() const{                         return this->highrange;                 }                  bool iswind();                 bool iswoodwind();                 bool isbrass();                 bool iskeyboard();                 bool ispercussion();                 bool isstrings();                  friend std::ostream &operator <<(std::ostream &os, const instrument &instrument){                 } };  #endif 

here percussion.h class

#ifndef percussion_h #define percussion_h  #include "instrument.h"  class percussion : public instrument{         private:                 bool struck;         public:                 percussion(std::string name, std::string sound, std::string lowrange, std::string highrange, bool struck) : instrument(name,sound,lowrange,highrange){                         this->struck=struck;                  }                  bool isstrucked() const {                         return this->struck;                 }                  bool ispercussion() {                         return true;                 }                  std::string gettype() const{                         if(this->struck){                                 return "struck";                         }                         else{                                 return "";                         }                 }                  friend std::ostream &operator <<(std::ostream &os,  percussion &percussion){            //the error stems line of code           //apparently, getname() method in base class isn't called                             os<<percussion.getname();                  }  };  #endif 

here implementation file instrumentapp.cpp

 #include <iostream>  #include <string>  #include <sstream>  #include <cstdlib>   #include "instrument.h"   #include "percussion.h"  #include "strings.h"  using namespace std;    int main() {      percussion timpani("timpani", "boom", "d2", "a2", true);     cout << timpani << endl;      percussion harp("harp", "pling", "cb1", "f#7", false);     cout << harp << endl;       return 0; } 

the problem here wasn't returning os object when overloaded << operator.

the fix follows in percussion.h file

friend std::ostream &operator <<(std::ostream &os,  percussion &percussion){          os<<percussion.getname();          return os;   }