To Copy, or not to Copy, that is the question

[thelink2012]

The objects we are implementing here are just a newtype over a raw pointer with no Drop (as the objects are managed internally by IUP). So prehaps they should be Copy?

Currently it does not implement Clone either and there is a fn dup(&self) -> Self; in the Element trait for that purposes, this should probably be removed when this issue is resolved...

The downside I see by using Copy is that it might look like we are not dealing with a object. And the downside I see by using Clone is it gives a look of deep copying the entire object but we'll just be copying a loose handle.

However I see a huge upside in using Copy, we'll not need to wrap the objects in a Rc<RefCell<_>> and add a scope, and add a clone call for every closure callback that wants access to those as seen in the counter.rs example (and seen worser in the older counter example).

[thelink2012]

/cc @dcampbell24

[thelink2012]

Elements are now (as of 10780ee87) Copy+Clone but there are some things left to do before closing this issue:

• Get rid of the Element::dup method.
• Experiment for a while with this Copy model, until now seems better than before.