Problem With STL List Sort

[dremmuel]

Hello,

I am having a problem sorting a large list. Below is an example.

#include <iostream>
#include <list>
using namespace std;

void main()
{

	list<int> ints;
	for(int k=0;k<50000;k++) ints.push_back(k);
	ints.sort();
	cout << "ints.size(): " << ints.size() << endl;
}

The number of integers left in ints is 17232, meaning some were lost during ints.sort(). I would like to know what the cause of the problem is and the sorting algorithm used in sort(). Thank you for this information or a link to it.

dremmuel

[JohnW@Wessex]

Works fine in Visual Studio 2005.

[dremmuel]

Maybe it's just an issue with Visual Studio 6.0. I was able to sort the list by sorting parts of it and merging the parts together. I suppose it will have to do until I can get my hands on Visual Studio 2005.

Thanks for the information John.

[JohnW@Wessex]

I just tried it in Visual Studio 6.0 and got the same results as you.

The maximum number of elements it can sort seems to be 32767, which is the maximum positive value of a 16bit signed integer.

It appears to roll-over its count after 32767

50000 - 32768 = 17232

[MikeAThon]

See "FIX: Listing Sort Function Removes Elements" at http://support.microsoft.com/kb/240014

It's an "off by one" coding error. Fixed in Visual C++ .NET.

Scary, isn't it?

Mike