[boost] Re: [pointer container] copyability

From: Bob Bell (belvis_at_[hidden])
Date: 2005-04-27 16:20:03

Thorsten Ottosen <nesotto <at> cs.auc.dk> writes:
> 
> "David Abrahams" <dave <at> boost-consulting.com> wrote in message 
> news:uacnkw0cr.fsf <at> boost-consulting.com...
> | "Thorsten Ottosen" <nesotto <at> cs.auc.dk> writes:
> | > Pick up you're favourite book on OO and on STL and see if the
> | > programming techniques look alike.
> |
> | That's a very parsimonious explanation.  It would be nice if you'd try
> | to make it a bit clearer in the context of the question of duplicating
> | objects, and show how it justifies a choice to prohibit ptr_containers
> | from acting like proper values.
> 
> the first reason must be its damn expensive without move-semantics.

So is std::vector<std::map<std::vector<std::string>, std::set<int> > >,
std::vector<int> >. Should the standard library prevent users from using
copy construct/copy assignment syntax with this data structure?

> the second reason is that value-based and OO programming are different and are 
> best
> kept seperate; there are different idioms, different parts of the langauge is 
> being used.

How do you know ptr_containers will be used in OO contexts? Why can't a user
use such containers to simply keep track of values?

One of the great strengths of C++ is that it doesn't try to force the
programmer into any one programming paradigm. Your justification for
denying ordinary copy syntax is against this spirit.

Bob