Re: [Boost-users] How to delete all vertices and edges in BGL

From: Doug Gregor (dgregor_at_[hidden])
Date: 2005-07-12 16:06:31

On Jul 12, 2005, at 8:52 AM, Jeremy Graham Siek wrote:

> Hi Guys,
>
> On Jul 12, 2005, at 8:25 AM, Douglas Gregor wrote:
>> The major problem here is that you shouldn't be dereferencing
>> vertices(databaseGraph).second, because it is a past-the-end iterator.
>> You could rewrite the loop as:
>>
>> while (vertices(databaseGraph).first != 
>> vertices(databaseGraph).second)
>> {
>>    b = *vertices(databaseGraph).first;
>>    clear_vertex(b, databaseGraph);
>>    remove_vertex(b, databaseGraph);
>> }
>
> But the above loop could also have problems due to vertex iterator
> invalidation
> caused by remove_vertex... it depends on the graph used.

?

We're not storing any iterators, so there's nothing to invalidate. 
Granted, the loop is horribly inefficient when VertexListS=vecS, and 
clear() is better, but this will work.

        Doug