c++ - Working with a vector of a class -

i newbie @ c++, , starting work container called classes.

i working on program object defined, , stored inside vector.

the program follows, , description of error got.

this "car.h"

#ifndef car_h_guard #define car_h_guard  class car{      int v;//the velocity      int loc;//location  public:      //default constructor, copy constr., cp. assgnmt. optr., destructor     car();     car(const car& j);     car& operator=(const car& j);     ~car();      void set_v(int);    //sets velocity      void set_pos(int);  //sets position      int get_v (){return((v));}//returns velocity     int get_pos(){return(loc);}//returns position  }; #endif 

this "car.cpp"

#include "car.h" #include <iostream>  using namespace std;  //constructor car::car() {      v=1;     loc=0;  }  //copy constructor car::car(const car& j){      v=j.v;     loc=j.loc;  }  //copy assignment operator  car& car::operator=(const car& j){      v=j.v;     loc=j.loc;      return *this;  }  //destructor car::~car () {      delete &v;     delete &loc;  }  //sets velocity void car::set_v(int p){      v = p;  }  //sets position void car::set_pos(int l){      loc = l;  } 

i have tried create "move constructor", having copy assignment operator. following code involving vector of objects work.

#include "main.h" #include "car.h" #include <iostream> #include <vector>  using namespace std;  //update car position void update (vector <car> &cr){      //changes state of cars, eg.     (int c = 0; c<cr.size();c++){         cr[c].set_v(1);         cr[c].set_pos(100);     }  }  int main(){      //a vector of cars     vector<car> cat;      car j;     j.set_v(100);     j.set_pos(99);     cat.push_back(j);      //new cars enters road     j.set_v(120);     j.set_pos(77);     cat.push_back(j);      j.set_v(80);     j.set_pos(55);     cat.push_back(j);      //updating cars     update(cat);      //output     (int = 0; i<cat.size(); i++){          cout << cat[i].get_v()<<" velocity of car "<<i<<".\n";         cout << cat[i].get_pos()<<" position of car "<<i<<".\n";      } } 

and following error, looked on internetz.

main(8852) malloc: * * * error object 0x7fff5fbff630: pointer being freed not allocated * * * set breakpoint in malloc_error_break debug abort trap

although might compiler incompability (i wrote in xcode... , uses g++, on mac 10.6.8 ...), code give output when there 1 car in vector. when tried introduce other cars, receive malloc error. wondering whether missing class definition, or somehow botched data-types, or pointer referencing. there issue values outputted if tried non-trivially manipulate update function.

i have tried pass instead vector of pointers (to class) update function; still have trouble inserting new elements vector. site helpful in helping me learn class structure, , pointers.

thanks reading long problem.

one uses delete on things 1 has used new. never delete wasn't separately allocated new. these lines in car destructor are... destructive (pardon pun):

delete &v; delete &loc; 

delete these lines -- they're totally unnecessary , they're source of problem. time you'd use delete in destructor when you've used new allocate object in constructor -- or when pointer-to-object passed constructor understanding object responsible deleting pointer when object destructed.