[RFC] Deprecate non-standard constructors in std::pair

[Jonathan Wakely]

On 07/04/21 15:41 +0300, Ville Voutilainen via Libstdc++ wrote:
>On Wed, 7 Apr 2021 at 15:31, Jonathan Wakely via Libstdc++
><libstdc++@gcc.gnu.org> wrote:
>> I propose that we deprecate the constructors for C++11/14/17/20 in
>> stage 1, and do not support them at all in C++23 mode once P1951 is
>> supported. I have a patch which I'll send in stage 1 (it also uses
>> C++20 concepts to simplify std::pair and fix PR 97930).
>>
>> After a period of deprecation we could remove them, and support P1951
>> for -std=gnu++11/14/17/20 too so that {} continues to work.
>
>The proposal sounds good to me.

Thanks. I've created https://gcc.gnu.org/PR99957 so I don't forget.