Re: [Boost-users] [Boost.Graph] Compiler warning in dijkstra_shortest_paths

From: Douglas Gregor (dgregor_at_[hidden])
Date: 2007-07-30 08:21:18

Ewgenij Sokolovski wrote:
> Hello. I use the Boost.Graph with the dijkstra_shortest_paths algorithm in my graph application. All works fine. But while compiling with the options -Wall -W I get a strange compiler warning:
>
> /usr/include/boost/graph/dijkstra_shortest_paths.hpp:80: Warning: »bfs_vis$m_decreased« is used in this function uninitialised
>
> This was the last line of the warning because it is quite long in its complete version. I translated the line above from German because I use a German version of g++, so maybe it sounds in the English version a little bit different. But the meaning remains the same:)
>
> Does anybody know what that is supposed to mean? Is something wrong with my program or is it a bug in dijkstra_shortest_paths?
>   
Neither, actually. g++ is optimizing something in the Dijkstra visitor 
and triggering a false warning in the process. This warning does not 
mean that there is a bug anywhere in the BGL or in your code.

    - Doug