R0 of this paper already proposed it, and LEWG didn't like it. First telecon it was discussed at (https://github.com/cplusplus/papers/issues/1303#issuecomment-1301074000) there was a poll to remove the apply part, 2-6-6-1-0.

This is very good information, I didn't expect this issue to have been discussed by the committee.
Thanks also for the valuable insights from others.

Hewill

Barry Revzin <barry.revzin@gmail.com> 於 2023年7月4日 週二 上午3:15寫道:


On Mon, Jul 3, 2023, 10:15 AM Kang Hewill via Std-Proposals <std-proposals@lists.isocpp.org> wrote:
Dear experts,

With the introduction of deducing this in C++23, variants in C++26 will have a member visit P2637R3, which is a great feature.
I wonder, is it good to also add member apply to tuple-like objects? For example:

   auto sum = std::tuple{0, 'a'}.apply(std::plus{});
   auto dist  = ranges::subrange{...}.apply([](auto i, auto s) { return s - i; });

Is this consistency superfluous, or does it have some value? One benefit I can think of is that this enables us to write the form of
  
   tuple.apply(...).apply(...).apply(...).apply(...)

which may be an enhancement. What do you think?

Hewill

R0 of this paper already proposed it, and LEWG didn't like it. First telecon it was discussed at (https://github.com/cplusplus/papers/issues/1303#issuecomment-1301074000) there was a poll to remove the apply part, 2-6-6-1-0.

Barry