[Boost-users] set_difference with lists strangeness

From: Torsten Sadowski (tsadowski_at_[hidden])
Date: 2008-05-06 07:35:47

Hi,

I have a bug when using set_difference with lists which puzzles me.  
The code runs like this:

list<int> nids,gnids,rnids;

//fill nids and gnids

   nids.sort();
   gnids.sort();
   set_difference(nids.begin(), nids.end(),
                   gnids.begin(), gnids.end(),
                   rnids.begin());

It works as expected in debug mode (-O0) but crashes in optimized  
mode (-O3). rnids is still empty after set_difference and the program  
crashes as soon as I try to use rnids. If I use a vector of the right  
size for rnids everything works. Obviously the memory allocation for  
the receiving list is optimized away. Is this not against the idea of  
the STL algorithms?

Cheers, Torsten