is this a memory leak?

[that_guy]

I am trying to make a vector class with some functions and operators, and I was wondering if the following would cause a memory leak:

class vector
{
  private:

  int size;
  double *value;

  public:

  vector(vector&);
  vector(int);
  vector() { value = NULL; };
  ~vector () {delete [] value;};


  int get_size() { return size; };
  double &operator () (int a) { return (value[a]); };

  vector &operator + (vector&);
};  

vector::vector (int a)
{
  size = a;
  value = new double[size];
}

vector::vector (vector& a)
{
  size = a.get_size();
  value = new double[size];
  for (unsigned i=0; i<size; ++i)
    value[i] = a(i);
}

vector &vector::operator+ (vector& a)
{
  vector temp(size);
  for (unsigned i=0; i<size; ++i)
    temp(i) = value[i] + a(i);
  return (*(new vector(temp)));  // does this statement cause a leak???
}

This statement will run millions of times so I want to make sure that it's not leaking memory all over the place. Any help on this would be much appreciated.

[a18u14]

#run the program & check the resources being used by the command

lsof -p process-id

[that_guy]

I ran some simple tests and it is causing a memory leak.

But how can I change the + operator function to not leak memory?

I've tried many other varieties but none of them work other than returning the local variable itself (which is not a good way to do it anyways).

[manishgurnaney]

you can change the Prottotype of the overloaded operator to:-

vector operator +(vector &v){
vector temp;


return temp;
}

for this you also need to overload = operator.

[that_guy]

I tried your suggestion, but it won't compile now.

This code:

#include <iostream>

class vector
{
  private:

  int size;
  double *value;

  public:

  vector(vector&);
  vector(int);
  vector() { value = NULL; };
  ~vector () {delete [] value;};

  int get_size() { return size; };
  double &operator () (int a) { return (value[a]); };

  vector operator +(vector a){
    vector temp(size);
    for (unsigned i=0; i<size; ++i)
      temp(i) = value[i] + a(i);
    return temp;
  }
  
  vector &operator =(vector& a){
    for (unsigned i=0; i<size; ++i)
      value[i] = a(i);
    return *this;
  }
  
};  

vector::vector (int a)
{
  size = a;
  value = new double[size];
}

vector::vector (vector& a)
{
  size = a.get_size();
  value = new double[size];
  for (unsigned i=0; i<size; ++i)
    value[i] = a(i);
}

int main(void)
{
  vector x(100);
  vector y(100);
  for (unsigned i=0; i<100; ++i)
  {
    x(i) = 3.0;
    y(i) = 0.0;
  }

  y = x+x;

  return 0;
}

Gives the error message:

In function 'int main()':
error: no match for 'operator=' in 'y = vector::operator+(vector)(vector(((vector&)(& x))))'
note: candidates are: vector& vector::operator=(vector&)

[manishgurnaney]

sorry Its my Bad, Please comment the code :-

/* vector &operator =(vector& a){
for (unsigned i=0; i<size; ++i)
value[i] = a(i);
return *this;
}
*/
there is no need to overload the = Operator.