[Seqan-dev] Skiplist does not find existing key

[Fabian Buske <f.buske@uq.edu.au>]

Hi,

I observed a rather peculiar phenomenon for the Skiplist map 
specialisation, a data type I use quite extensively.

Using a custom key class and comparator the skiplist sometimes does not 
find a key that has been inserted into the map. Since the skiplist is a 
randomised data structure this behaviour occurs by chance.

When using the iterator to go through the Skiplist the element will 
actually be output. I observed that the order of the objects (keys) in 
the output is not the ordered lists of keys according to the comparator 
(which I was expecting) but to the order in which the keys where 
inserted into the map. I'm not sure if this is intended.

I created a ticket for this phenomenon, which has an extended test_map 
class attached demonstrating this behaviour:
http://trac.mi.fu-berlin.de/seqan/ticket/589

This phenomenon may have serious consequences on any application relying 
on Skiplists.

Best,
Fabian

--

Fabian Buske
Institute for Molecular Bioscience
The University of Queensland
Brisbane, Qld. 4072 Australia
Phone: (61)-(7)-334-62608