[gecode-users] Shared datastructures & CopyNode fields

[Lars Otten]

Hello,

while delving into the details of the DFS engine I encountered an unclear
statement in the documentation for Space::clone(bool, unsigned long int&).
It is written that "[...] a clone of the space is returned. If \a shared is
true, all shared datastructures are shared among the clone on the original
space. [...]"

What exactly are these "shared datastructures" here? Furthermore, in a
strict sense, isn't it strange to define the sharing of datastructures that
are, judging by their name, already shared? Do you perhaps mean /shareable/
datastructures?

Another issue on which I'd grealy appreciate some clarification: What
exactly is the purpose of the fields _alt and _last in the class
Gecode::Search::CopyNode? I have some rough ideas but as I've still not
completely understood all of the DFS code it's hard to verify those...

Thanks,

/Lars