Re: [boost] variant invariant

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-08-04 15:48:20

AMDG

Emil Dotchevski wrote:
>>> Also, I am not necessarily advocating strong exception guarantee. I
>>> would be fine if the semantics of operator= were such that it may
>>> leave the object in a particular unusual state. The problem is that as
>>> it is now, it may leave the object in a seemingly OK state.
>>>       
>
> Yes, I was aware of this workaround and of the one Mathias mentioned.
>
> However, variant<foo,bar,blank> and variant<wrapper<foo>,wrapper<bar>>
> aren't the same as variant<foo,bar>. I'm questioning the rationale of
> the current variant::operator= semantics, not necessarily looking for
> a way to work around them.
>   

It doesn't seem unreasonable to require boost::blank to be listed,
in order to allow a variant to be left in a "particular unusual state"

In Christ,
Steven Watanabe