Peter Dimov wrote:
Thorsten Ottosen wrote:
If you not willing to accept that value-based programming and OO programming are different disciplines, we will never agree on this one. Period.
Entity/identity-based and value-based are different, no question. What is controversial is your claim that the mere presence of a virtual function by necessity implies that the identity of the object is important (as opposed to its value).
I think I'm merely saying value-sematics are not the most important to worry about, even for shape objects.
To give an example, in the texbook OO hierarchy Shape -> Circle, Square, ... the identities of the objects play no role, they are pure values. You can copy a collection of shapes and you'll have a perfect replica of the original.
Sure, and ptr_container also allows you to copy the collection, albeit a little less convenient than with operator=(). -Thorsten