Why prevent copies?

[g-pechorin]

This is a "it works for me, what am I missing?" issue;

Why prevent copying?

I'm working with the generators to implement iterators for a complex container. If we/I assume that user-code is smart enough to copy their members, why prevent the generators from copying?

[c-smile]

I suspect that copy operation is not applicable to generators as it may create forks...

But I think that move semantics for generators does make sence - to support swap operation at least.
And swap is needed to support iterators on hierarchical trees for example.

Why do you need to copy generator instance? What is your use case ?

[g-pechorin]

I'm trying to use the generator as the guts of an iterator. The container is (homemade and) formed from a linked list of std::vector and I lack (the free time for) a more inspired solution.

If I want member variables that are $generator instances then I need copy (or move I guess) so that I can return the instances - right?

I think that I'm coming from a "pure functional" (Scala) background here so I hadn't considered that the $generator would be relying on "external state" to get its job done.

• my $generator which works by emitting a pointer to the next element
• my iterator which wraps the $generator
• iterator emitting a pointer to the next element which comes out of the $generator

[c-smile]

As far as I can see you have explicit copy constructor of the generator, right?
If so then conceptually that is right thing to do.

I am disabling blind copy constructor to prevent cases when C++ creates copies of variables under the hood. Calling yield on copy will not update state of the copied iterator for obvious reasons.