operators overloading, strange seg fault

[fninigi]

Hello!

I was given an exercise (the main() part) by my teacher and was supposed to write functions so that it would work. But I keep having seg fault. It's ok if the

TSeries series4=series1(2,4);
cout<<"Series4: "<<series3<<endl;
lines are commented. I would be grateful for your help.

    #include <iostream>
    class TSeries{
        public:
            TSeries()
                {
                     _size = 0;
                     _capacity = 0;
                     _tab = NULL;
                }
    
    
            TSeries(float *tab, const int size)
            {
                     _tab = new float[size];
                    for(int i =0;i<size;i++) _tab[i] = tab[i];
                    _size = size;
            }
    
            ~TSeries(){delete [] _tab;}
    
            TSeries & operator+=(float value){return insert(value);}
            TSeries & operator,(float value){return insert(value);}
            TSeries & operator+(const TSeries & s)
            {  
              //  if(this->_size != s._size) std::cout<<"Size doesn't match!"<<std::endl;
                /*else
                {
                    std::cout<<"whee";
                    for(int i; i<this->_size;i++)
                    {
                        //this->_tab[i] += s._tab[i];
                        std::cout<<"nothing";
                    }
                return *this;
                }*/
            //std::cout<<"sth";
            }
    
            TSeries & operator()(int position1, int position2)
            {
               // return *this;
            }
    
            TSeries & insert(float k)
                {
                    if(_size >= _capacity) Enlarge();					
                    _tab[_size++] = k;
    	            return *this;
                }
            friend std::ostream & operator<<(std::ostream & out, const TSeries & s);
       
    
        private:
            int _size, _capacity;
            float *_tab, *_itr;
            static int _nr;
    
    			void Enlarge()
    			{
    				_capacity = 2 * _capacity + 1; 
    				float *tmp = new float[_capacity]; 
    				
    				for( int i=0;i<_size;++i)
    				{
    					tmp[i] = _tab[i];
    				}
    				delete [] _tab;
    				_tab = tmp;
    			}
    };
    
    std::ostream & operator<<(std::ostream & out, const TSeries & s)
    {
        int przedostatni = s._size - 1;
        out<<"(";
        for(int i =0;i<s._size;i++)
        {  
            out<<(int)s._tab[i];
            if(i != przedostatni)
                out<<",";
        }
        out<<")"<<std::endl;
    }
    
    using namespace std;
    int main(int argc, char **argv) {
      TSeries series1;
      series1 += 1.,2.,4.,2.;
      cout<<"Series1: "<<series1<<endl;
     
      const int size=7;
      float tab[size] = {3.,3.,3.,4.,5.,1.,0.}; 
      const TSeries series2(tab,size);
      cout<<"Series2: "<<series2<<endl<<endl;
    
     
      TSeries series3 = series1+series2;
      cout<<"Series3: "<<series3<<endl<<endl;
      
      series1+=1.,0.,3.;
      series3=series1+series2;
      cout<<"           "<<series1<<endl;
      cout<<"          +"<<series2<<endl;
      cout<<"        ---------------------"<<endl;
      cout<<"Series3:   "<<series3<<endl<<endl;
      
      TSeries series4=series1(2,4);
      cout<<"Series4: "<<series3<<endl;
      
      return 0;
    }

[mutexe]

What are you trying to achieve with this line:
TSeries series4=series1(2,4);
?

Also, why are you trying to create a series4 variable when you don't even use it? (you're using series3 on the line after this).

[coder777]

The problem is the constructor on line12: You do not set _capacity. It remains uninitialized.

[fninigi]

Mutexe - my mistake, I was trygin to check sth, in original code the last line was:
cout<<"Serires4: "<<seires4<<endl;
And the main() was given by my tutor - the point of this exercise is overloading, not logic ;)

[fninigi]

Coder777 - I've followed your advice and changed the construkctor. Seg fault remains.

        TSeries(float *tab, const int size)
        {
                 _tab = new float[size];
                for(int i =0;i<size;i++) _tab[i] = tab[i];
                _size = size;
                _capacity = 0;
        }

[coder777]

_capacity must not be 0, it must be at least _size.

Line 97/107 is a problem. You make a shallow copy due to the lack of a copy constructor/operator. The program will crash because it tries to free the same memory twice.

[fninigi]

Unfortunately it's still not helping.

       TSeries(float *tab, const int size)
        {
                 _tab = new float[size];
                for(int i =0;i<size;i++) _tab[i] = tab[i];
                _size = size;
                _capacity = _size;
        }

Any other suggestions?

[coder777]

Where exactly does it crash? The best would be to use the debugger, but you might use some debugging cout.

Obviously your code is not complete. What about the operator+ on line 23 or the operator() on line 39? You use both.