Re: [boost] [bgl] Bug in depth_first_search (and therefore topological_sort...)

From: Loïc Joly (loic.joly_at_[hidden])
Date: 2006-07-24 18:04:52

Cromwell Enage a écrit :

> Why not just request that the corresponding
> documentation be amended to reflect the fact that both
> depth_first_search and topological_sort require
> non-empty graphs?  It's a simple matter of adding (0 <
> num_vertices(g)) as a precondition.  I'd rather not
> pay for extra runtime checks if my graphs are already
> guaranteed to contain vertices.

Does it have to require a specific test ? When iterating over a 
container from begin() to end(), I don't have to introduce some special 
cases to handle an empty container. It might be possible to do the same 
for topological_sort.

Anyway, if you believe such a test could really have any visible impact 
on performances, maybe two versions of the algorithms would be another 
option, just like std::vector<T>::at and std::vector<T>::operator[].

-- 
Loïc