>
>>intersect
>>minus
>
> Those are relatively easy to implement. What prevents you from adding
> them yourself ?
>

Absolute total lack of C++ knowledge which is probably not an excuse. I
was not realy asking someone to add it as I dont have need for it. It
was mere a theoretical question. Perhaps it could be a starting point
for me to start learning C++. On the other hand I dont want to cut my
teeth on C++ in such a "critical" piece of code.

Groete
Gerhardus