Dev-C++ error?

[TheVAL]

Hi!

I noticed a very strange behaviour of Dev-C++ compiler. I have a function which transforms a binary file (containing positive and negative integers as records) by moving all the integers one position (4 bytes) to the left (so the first record in the file is left `empty`). I have written a function like this:

void moveRecords(fstream & f) {
 f.seekg(0,ios::beg);
 int x=0,y=0;
 f.read((char *)&x,sizeof(int));
 if (f) {
  f.read((char *)&y,sizeof(int));
  while (f) {
   f.seekp(-4,ios::cur);
   f.write((char *)&x,sizeof(int));
   x=y;
   f.tellp();
   f.read((char *)&y,sizeof(int));
  }
 }
 f.clear();
 f.seekp(0,ios::end);
 f.write((char *)&x,sizeof(int));
 f.clear();
}

It works fine! Now, if I delete or comment the line `f.tellp();`, nothing works fine anymore - just some first integers are moved and after that a while loop is finished (so I guess some error occurs). And the funny part is that it happens only in Dev-C++ compiler - if compiled with Borland, I don't have to write this useless line of `tellp`.. Why is that and how to get rid of it? Because in the situation, I must use the Dev-C++.

[JohnW@Wessex]

Is it a large file?
Can you read it all into a container and then write it out again?

void moveRecords(fstream & f) 
{
    std::deque<int> value_list;

    int value;

    // Read it all in.
    while (f.read((char *)&value, sizeof(int)))
    {
        value_list.push_back(value);
    }

    // Remove the first.
    value_list.pop_front();

    // Write them back.
    std::copy(value_list.begin(), value_list.end(),  std::ostream_iterator<int>(f, ""));
}

(Untested)

[TheVAL]

No, it is not a large file - I tested the function on file having only 10 records in it.. But the thing is I have to demonstrate the operations within the file itself and I am not allowed to put all the contents of the file in the memory and then to forget about the file..