On 8.2.2012. 19:05, Hite, Christopher wrote:
On Tuesday, February 07, 2012 17:00:04 Andrey Semashev wrote:
BTW, I would really like to see optional< T& > optimized to store T* internally. I'm going to say something provacative here. I agree with Lucanus. I see no reason for optional<T&>. As far I can tell you could use a T*. The only justification I can think of is on system without memory protection you can build checks into operator*().
Maybe if you're mixing code with old libraries where T* might imply ownership you might use optional<T&> to imply no ownership and some temporary validity.
Perhaps we should define a new "smart pointer" called dumb_ptr<T> which can't be assigned into auto_ptr,unique_ptr,shared_ptr, or any pointer type which implies ownership.
Maybe I'm missing something, but I don't see the justification.
IMO it seems that, yes, you are making the same mistake as Lucanus, thinking about "The Universe" only as/through your POV of your personal problem domain: a) (optional models optionally holding an object) + (objects can be held by value and by reference) = optional<T&> perfectly logical b) creating special cases (e.g. for T&) creates special problems in generic code -- "What Huxley teaches is that in the age of advanced technology, spiritual devastation is more likely to come from an enemy with a smiling face than from one whose countenance exudes suspicion and hate." Neil Postman