Subject: Re: [boost] [variant] Heads-up!
From: Emil Dotchevski (emildotchevski_at_[hidden])
Date: 2019-04-29 20:00:29
On Mon, Apr 29, 2019 at 12:47 PM Steven Watanabe via Boost <
> On 4/29/19 1:08 PM, Antony Polukhin wrote:
> > <snip>
> > This discussion was considered. Please see the two comments from
> > Nikita Kniazev
> From the PR:
> > The nullified recursive_wrapper is in a valid but unspecified state
> Strictly speaking this is true, but it is
> backwards incompatible because the state
> was not valid in previous versions.
This makes it sound like the only problem is that it is a breaking change,
but just because we label that state as "valid" doesn't mean that we can
also say that we're providing the never-empty guarantee. If we care about
correctness at all, if the never-empty guarantee is not dropped, the state
in question is not valid and therefore we're violating the basic guarantee.
Boost list run by bdawes at acm.org, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk