Re: [boost] [optional] Thoughts on disallowing assignment for wrapped references.

Subject: Re: [boost] [optional] Thoughts on disallowing assignment for wrapped references.
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2011-09-03 23:34:41

On Sat, Sep 3, 2011 at 7:55 PM, Mostafa <mostafa_working_away_at_[hidden]>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