Joel de Guzman <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Fernando Cacciola <[EMAIL PROTECTED]> wrote: > > >> Even if I agree with you that an optional<T> should not be a T, > >> an optional<T> is definitely not a pointer to T. > >> > > Definitely! > > If HTML had blinking banners I think I'd use one to state this :-) > > Nor should it model a pointer. > It tries not to model a pointer at least.
The OptionalPointee concept was coined to stress this fact, by formalizing the syntatic meaning of operators * and -> independently of pointers. What I'm defending here is the idea of giving operators * and -> a meaning on their own: the possibly undefined value of its operands. That this choice of operators still makes the appearance that optional<> models a pointer I need to address on the documentation by a better formalization of the concept. > That was my point and the point of others who dislike *opt. > > > > Yet iterators are not pointers either but they do use > > operators * and -> > > Iterators are not pointers, but they model the pointer. > > >> Right. In fact, looking at it more closely, I *could* almost agree with you > >> that an optional<T> is not a T. There is in fact a getter function (get). > >> In fact all three (tuple, optional and variant) have a get function. That's > >> fine, yet, here again, the optional does not jive well because it returns > >> access *by pointer* whereas both tuple and variant return access by > >> reference. > >> > > This get() issue we agree should be fixed. > > Agreed. If there's a way to get at the values through a generic get > function that unifies the access of optional with variant such that I > can think of optional as an optimized specialization of variant<T, none>, > I would be very happy. With such an interface, I can simply ignore > the pointer-like interface, if you wish to keep it ;-) > All right, we're settled then! > > Thanks you very much! And BTW, kudos for such a well engineered > library! Spirit has been using it since v1.7 and I am very happy with > it. The comments I gave so far are merely my opinion. You are of > course free to have your own preferences :-) > > Keep up the good work! > Thank you! Fernando Cacciola _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
