On Sat, Sep 3, 2011 at 7:55 PM, Mostafa <mostafa_working_away@yahoo.com>wrote: [...]
Aren't we all? But there are differing notions of consistency floating around. I'm motivated by consistency for the assignment operator of optional<T&>, Fernando's motivated by consistency of programming w.r.t. to template programming and use of optional in general. And as Fernando pointed out, it may not be possible to satisfy all these notions simultaneously. My thought was, and continues to be that if all these notions of consistency can't be satisfied simultaneously, then instead of satisfying some fully and others partially, why not just disallow those operations that are partially consistent. Or more specifically, what are the implications of just disallowing those operations that are partially consistent?
One implication would be a breaking of existing code. Another implication would be greater difficulty in using optional<T> in a generic context when T could be a reference type. - Jeff