----- Original Message ----- From: "David Abrahams" <[EMAIL PROTECTED]> To: "Boost mailing list" <[EMAIL PROTECTED]> Sent: Tuesday, December 10, 2002 10:00 PM Subject: Re: [boost] Formal review: Optional library
> "Fernando Cacciola" <[EMAIL PROTECTED]> writes: > > > > I still don't like to think of optional<> as a container, so I still > > don't like this reset. > > Do you really think of auto_ptr and shared_ptr as containers? They > seem to have little or nothing in common with any of the standard > containers. > OK. After further thinking I agree that optional<> is as much as a container as a smart pointer -not much really-, meaning that you pass a value which is contained within the wrapper and which you can access it. > > My motivation against this is just to prevent potential problems with > > optional<bool>, but if we collectively conclude that those problems > > are not so much important, I will add the safe_bool and > > make sure to tell every not to use optional<bool> (and use tribool instead) > > or else to use it with caution. > > I don't think any special warnings are needed; the problem case you > cite seems contrived to me. > Perhaps. Anyway, if I add safe_bool (and it looks like I will) I will explain the potential problems in the docs just in case. > > I'm not sure what would be effect of removing deep-constantness. > > It would definitely allow the leaner interface you are proposing, > > Well, deep-constantness is utterly inconsistent with the pointer-like > semantics you claim to be implementing. A pointer-ish optional > component is a fine idea, but why not follow through all the way with > the idiom? > How is deep-constantness utterly incosistent with pointer-like semantics? > > This is a possibility. > > I could accept something like this, though I constantly see > > people complaining about lack of deep constantness on wrappers like > > optional<> > > What do others think? > > Is it a wrapper or a pointer? > Is a wrapper which acts partially like a pointer. Fernando Cacciola _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
