iostream using pointer

[purusingh]

typedef TArray<CShape*> CShapes;
typedef TArrayIterator<CShape*> CShapesIterator;

CShapes *shapes = new CShapes(10, 0, 10);


void TDrawWindow::save()
{

ofstream os("c:\\abc.txt");
CShapesIterator i(*shapes );

while (i) {
CShape *p = i++;

os<<p;
}

}

is it correct or not?
if it is correct then how to retrive it from file

I have done so but it is not working.


void TDrawWindow::Open()
{
ifstream is("c:\\abc.txt");


shapes ->Flush();

unsigned numPoints;

is >> numPoints;

while (*numPoints--) {
CShape shape;
is >> shape;
shapes->Add(&shape);
}

Invalidate();

}

[CornedBee]

No, not correct. You're only saving the pointer value.
Unless there is a specific overload of << for TObject * or TShape *. If not you'll have to do
os << *i;
and overload the << operator for const TShape &.

[purusingh]

Thanks



friend ostream& operator<< ( ostream& os, CShape& shape );
ostream& operator<< ( ostream& s, CLine& dt )
{
s << shape .pt1 << shape .pt2 << '\n';;
return s;
}

this is what I have done for direct access.
But How to overload for pointer

[Zaei]

Originally posted by purusingh
Thanks



friend ostream& operator<< ( ostream& os, CShape& shape );
ostream& operator<< ( ostream& s, CLine& dt )
{
s << shape .pt1 << shape .pt2 << '\n';;
return s;
}

this is what I have done for direct access.
But How to overload for pointer

You dont have to overload for pointers. Just dereference p.

Z.

[purusingh]

please show me how to use it in these functions


void TDrawWindow::save()
{

ofstream os("c:\\abc.txt");
CShapesIterator i(*shapes );

while (i) {
CShape *p = i++;

os<<p;
}




void TDrawWindow::Open()
{
ifstream is("c:\\abc.txt");


shapes ->Flush();

unsigned numPoints;

is >> numPoints;

while (*numPoints--) {
CShape shape;
is >> shape;
shapes->Add(&shape);
}

Invalidate();

}

[CornedBee]

Didn't I already?

while (i) {
  CShape *p = i++;
  os<<*p;
}

And make the prototype of the << operator
ostream& operator<< ( ostream& s, const CLine& dt);

[purusingh]

yes I did so but it is not working.

[CornedBee]

In that case my knowledge fails.

[Zaei]

In your Load function, you read the number of shapes saved. You never save that value in your save function.

Z.

[Zaei]

Also, while(*numPoints--) should be while(numPoints--), since it isnt a pointer value.

Z.