Re: [Boost-users] set_difference with lists strangeness

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-05-06 15:47:04

AMDG

Torsten Sadowski wrote:
> 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?
>   

This is not really a Boost question.

try using std::back_inserter(rnids) for the output.

In Christ,
Steven Watanabe