Subject: Re: [boost] [variant] Heads-up!
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2019-04-29 20:50:09
AMDG
On 4/29/19 2:28 PM, Matt Calabrese wrote:
> On Mon, Apr 29, 2019 at 4:23 PM Matt Calabrese <rivorus_at_[hidden]> wrote:
>> <snip>
>> Stressing that, as Steven points out, this wouldn't violate the
>> never-empty guarantee *if* after stealing you were able to
>> default-construct something on the right-hand side and update the
>> discriminator accordingly
>
> Continuing on this thought, you don't necessarily have to
> default-construct on the right-hand side to satisfy the never-empty
> guarantee here. If the left-hand side also happens to currently
> contain a recursive_wrapper, or something that is
> nothrow-move-constructible, it can be moved into or swapped with rhs.
>
That's true, but it doesn't help much, because
it only applies to assignment, not construction.
In Christ,
Steven Watanabe