C++ - Simple - nested while loops never terminate?

Question

I'm just revising some file i/o for C++. Writing a program that prints its own source code to the terminal without comments

Here are the loops in question WORKING with if statements

while (!inputstream.eof())
{
 if(in_comment == false)
    {
      inputstream.get(temp);
      if(temp == '/')
        {
          inputstream.get(temp1); 
          if (temp1 == '*')
            {
              in_comment = true;

            }
          else
            {
              inputstream.putback(temp1);
            }
        }

      cout << temp;
    }

  if(in_comment == true)
    {
      inputstream.get(temp);
      if(temp == '*')
        {
          inputstream.get(temp); 
          if (temp == '/')
            {
              in_comment = false;
            }
        }
    }
}

And here they are NOT working with while loops

while (!inputstream.eof())
{
 while(in_comment == false)
    {
      inputstream.get(temp);
      if(temp == '/')
        {
          inputstream.get(temp1); 
          if (temp1 == '*')
            {
              in_comment = true;
             break;
            }
          else
            {
              inputstream.putback(temp1);
            }
        }

      cout << temp;
    }

  while(in_comment == true)
    {
      inputstream.get(temp);
      if(temp == '*')
        {
          inputstream.get(temp); 
          if (temp == '/')
            {
              in_comment = false;
            }
        }
    }
}

I would have expected the eof marker to cause the program to break out of the outer while loop but it doesn't. Why is this?

Thanks

Answer 1

Your inner loops do not break on eof so you get an endless loop - simple as that. The outer loop only gets a chance to break when the inner loops are left. The working example has no inner loops, so the outer loop can end.