Thread: How can I get ifstream's getline function to include leading whitespaces?

Hi All,

I am trying to read in lines in a text file, and the leading whitespaces are important! However the getline function isn't reading in the leading whitespaces. Is this a normal way for getline to work? And is there a way around this?

Thanks for the help!

My mistake: getline does NOT ignore leading whitespaces. I checked the binary tree I was reading chars into and it was the correct length. But, it doesn't PRINT spaces.

I'll post the printing code involved (in order of function call):

Code:

const string mazeRow::toString() const
{
   points.print();
   string s;
   return s;
}

points is a binNode<mazePoint> object, so this function is called:

Code:

template <>
void binNode<mazePoint>::print() const
{
   if (left != NULL) left->print();
   std::cout << nodeData.toString();
	if (right != NULL) right->print();
}

And here is the toString function for the node...

Code:

const string mazePoint::toString() const
{
   stringstream ss;
   string s;
   ss << point_type;
   ss >> s;
   return s;
}

Does string stream ignore whitespaces or something?

Correction: it ignores ALL whitespaces. Not just leading ones.

I managed to solve the problem by replacing

Code:

stringstream ss;
   string s;
   ss << point_type;
   ss >> s;
   return s;

With

Code:

   cout << point_type;
   string s;
   return s;

Good point! This worked:

Code:

   string s;
   s = point_type;
   return s;

I have a separate toString function which does the following:

Code:

   points.print();
   string s;
   return s;

This is calling a print() function which in turn calls the previous toString function. I've tried capturing the output but it doesn't work! Like this:

Code:

   stringstream ss;
   string s;
   ss << points.print();
   ss >> s;
   return s;

This is the compiler error I receive:

Code:

In member function 'const std::string mazeRow::toString() const':
assign3.cpp:193: error: no match for 'operator<<' in 'ss << ((const mazeRow*)this)->mazeRow::points. bintree<dataType>::print [with dataType = mazePoint]()'

Is there any way around this?

Your print function returns no data, and accepts no data, so you can't do anything other than what it wants to do. If redirecting that output seems like a good idea, then you need to change the way your print function works.