That's what I was thinking, it's hard to predict the output of some program
given that the only guarantee is "valid but unspecified" state. I know
basically no implementation does such thing, but if they do, there is
really no way to know if it's safe or not. In my opinion, we should have
some guarantee saying which operation will and will not work

On Wed, Jan 22, 2025 at 8:30 AM Ivan Matek via Std-Proposals <
std-proposals_at_[hidden]> wrote:

>
>
> On Wed, Jan 22, 2025 at 5:23 PM Ville Voutilainen via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
>
>> On Wed, 22 Jan 2025 at 18:16, Gia Phan via Std-Proposals
>>
>>
>> > For example, assignment and destruction are obvious, but what about
>> something like resize(), reserve()? Shouldn't we have some clearly defined
>> behavior?
>>
>> We do.
>>
>
> I guess this depends on what you mean by "clearly defined". I believe
> result of this program is not clearly defined as in we know what it will
> output:
> int main()
> {
> std::string s{"abc"};
> auto s2 = std::move(s);
> s.resize(5,'x');
> std::print("{}",s);
> }
> (and that is intentional, since in theory because of SSO it is faster to
> leave source of move unmodified, although no implementation does that).
>
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