[boost] Re: Re: Formal review: Optional library

2002-12-17 Thread Fernando Cacciola
"Rob Stewart" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > From: David Abrahams <[EMAIL PROTECTED]> > > Date: Sun, 15 Dec 2002 10:29:23 -0500 > > Content-Type: text/plain; charset=us-ascii > > X-Mailman-Version: 2.1b3 > > Reply-To: Boost mailing list <[EMAI

Re: [boost] Re: Re: Formal review: Optional library

2002-12-17 Thread Rob Stewart
From: "William E. Kempf" <[EMAIL PROTECTED]> > David Abrahams said: > > "William E. Kempf" <[EMAIL PROTECTED]> writes: > >> Augustus Saunders said: > > > >> I wouldn't be overly concerned. I'd find this to be a programmer > >> error (passing a type to a template that doesn't meet the template's >

Re: [boost] Re: Re: Formal review: Optional library

2002-12-17 Thread William E. Kempf
David Abrahams said: > "William E. Kempf" <[EMAIL PROTECTED]> writes: > >> Augustus Saunders said: > >> I wouldn't be overly concerned. I'd find this to be a programmer >> error (passing a type to a template that doesn't meet the template's >> requirements). Concept checking libraries can even b

Re: [boost] Re: Re: Formal review: Optional library

2002-12-16 Thread David Abrahams
"William E. Kempf" <[EMAIL PROTECTED]> writes: > Augustus Saunders said: > I wouldn't be overly concerned. I'd find this to be a programmer error > (passing a type to a template that doesn't meet the template's > requirements). Concept checking libraries can even be employed to insure > such mi

Re: [boost] Re: Re: Formal review: Optional library

2002-12-16 Thread William E. Kempf
Augustus Saunders said: > William Kempf wrote: >>> Some people, mostly _me_, argued that this is not a good idea >>> because code would change meaning if optional<> is replaced >>> by a pointer. >> >>But it's going to change in any event, because optional<> _isn't_ a > pointer. >> >>But in generic

Re: [boost] Re: Re: Formal review: Optional library

2002-12-16 Thread David Abrahams
Augustus Saunders <[EMAIL PROTECTED]> writes: > William Kempf wrote: >>But in generic code you must follow the semantics of the concept, >>and optional<> isn't useable when a SmartPointer concept is >>required. Define the concept well enough, and optional<> becomes >>useful in generic code. I'

Re: [boost] Re: Re: Formal review: Optional library

2002-12-16 Thread Augustus Saunders
William Kempf wrote: >> Some people, mostly _me_, argued that this is not a good idea >> because code would change meaning if optional<> is replaced >> by a pointer. > >But it's going to change in any event, because optional<> _isn't_ a pointer. > >But in generic code you must follow the semantics

Re: [boost] Re: Re: Formal review: Optional library

2002-12-16 Thread William E. Kempf
Fernando Cacciola said: > "William E. Kempf" <[EMAIL PROTECTED]> escribió en el mensaje > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> >> Fernando Cacciola said: >> >> [snip William's comments about the interface with operator T&] >> > I agree with your comments about the interface with operato

[boost] Re: Re: Formal review: Optional library

2002-12-15 Thread Fernando Cacciola
"William E. Kempf" <[EMAIL PROTECTED]> escribió en el mensaje [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Fernando Cacciola said: > > [snip William's comments about the interface with operator T&] > I agree with your comments about the interface with operator T&. I show it in the post, actuall

[boost] Re: Re: Formal review: Optional library

2002-12-15 Thread Fernando Cacciola
"David Abrahams" <[EMAIL PROTECTED]> escribió en el mensaje [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > "William E. Kempf" <[EMAIL PROTECTED]> writes: > > > Fernando Cacciola said: > > > >> However, and very unfortunately, this _requires_ the properly well > >> defined relational operators to be

Re: [boost] Re: Re: Formal review: Optional library

2002-12-13 Thread Tanton Gibbs
> Thanks to the clear arguments made by the reviewers, I see the picture a lot > more clear now. > Specially the fact that optional<> is itself a container, or perhaps, a > union of T and nil_t. > But your previous post were you developed those concepts were very helpful > as an argument to keep th

[boost] Re: Re: Formal review: Optional library

2002-12-13 Thread Fernando Cacciola
"Augustus Saunders" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Fernando Cacciola wrote: > > >And pointers have historically been used to deal with optional > >objects precisely because they model this concept. > > I think this is important, and so I want

[boost] Re: Re: Formal review: Optional library

2002-12-13 Thread Fernando Cacciola
"Peter Dimov" <[EMAIL PROTECTED]> wrote in message 008901c2a2a8$9d1af430$1d00a8c0@pdimov2">news:008901c2a2a8$9d1af430$1d00a8c0@pdimov2... > From: "Fernando Cacciola" <[EMAIL PROTECTED]> > > "William E. Kempf" <[EMAIL PROTECTED]> wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >