[libcxx-commits] [libcxx] [libc++] LWG4025: Move assignment operator of `std::expected<cv void, E>` should not be conditionally deleted (PR #109363)

[Xiaoyang Liu via libcxx-commits]

https://github.com/xiaoyang-sde created https://github.com/llvm/llvm-project/pull/109363

## Introduction

This patch implements LWG4025: Move assignment operator of `std::expected<cv void, E>` should not be conditionally deleted.

## Reference

- [[expected.void.assign]](https://eel.is/c++draft/expected.void.assign)
- [LWG4025](https://cplusplus.github.io/LWG/issue4025)

Closes #105324


>From e5041855af20b5475b45ee9073643b434af4d52e Mon Sep 17 00:00:00 2001
From: Xiaoyang Liu <siujoeng.lau at gmail.com>
Date: Thu, 19 Sep 2024 22:16:31 -0400
Subject: [PATCH] [libc++] LWG4025: Move assignment operator of
 'std::expected<cv void, E>' should not be conditionally deleted

---
 libcxx/include/__expected/expected.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h
index f4ad455a19ea5e..e04e17d1ebe698 100644
--- a/libcxx/include/__expected/expected.h
+++ b/libcxx/include/__expected/expected.h
@@ -1493,8 +1493,6 @@ class expected<_Tp, _Err> : private __expected_void_base<_Err> {
     return *this;
   }
 
-  _LIBCPP_HIDE_FROM_ABI constexpr expected& operator=(expected&&) = delete;
-
   _LIBCPP_HIDE_FROM_ABI constexpr expected&
   operator=(expected&& __rhs) noexcept(is_nothrow_move_assignable_v<_Err> && is_nothrow_move_constructible_v<_Err>)
     requires(is_move_assignable_v<_Err> && is_move_constructible_v<_Err>)