From da6efe1a08463c917c6d8dfa6fb453612c98d055 Mon Sep 17 00:00:00 2001
From: yoh <kawasaki.liamg@gmail.com>
Date: Fri, 10 Feb 2023 14:29:25 +0900
Subject: [PATCH] expected: bad_expected_access<E>(#1066)

---
 reference/expected/bad_expected_access.md     |  8 +--
 .../expected/bad_expected_access/error.md     | 71 +++++++++++++++++++
 .../bad_expected_access/op_constructor.md     | 52 ++++++++++++++
 .../expected/bad_expected_access/what.md      | 64 +++++++++++++++++
 reference/expected/expected.void/value.md     |  2 +-
 reference/expected/expected/value.md          |  2 +-
 reference/expected/unexpected.md              |  4 +-
 reference/expected/unexpected/error.md        |  4 +-
 .../expected/unexpected/op_constructor.md     |  8 +--
 .../expected/unexpected/op_deduction_guide.md |  2 +-
 10 files changed, 202 insertions(+), 15 deletions(-)
 create mode 100644 reference/expected/bad_expected_access/error.md
 create mode 100644 reference/expected/bad_expected_access/op_constructor.md
 create mode 100644 reference/expected/bad_expected_access/what.md

diff --git a/reference/expected/bad_expected_access.md b/reference/expected/bad_expected_access.md
index b4ec99ce13..1f18724c7e 100644
--- a/reference/expected/bad_expected_access.md
+++ b/reference/expected/bad_expected_access.md
@@ -9,7 +9,6 @@ namespace std {
   template<class E>
   class bad_expected_access : public bad_expected_access<void> { ... };
 
-  // void特殊化
   template<>
   class bad_expected_access<void> : public exception { ... };
 }
@@ -24,10 +23,11 @@ namespace std {
 
 | 名前            | 説明           | 対応バージョン |
 |-----------------|----------------|-------|
-| [`(constructor)`](bad_expected_access/op_constructor.md.nolink) | コンストラクタ | C++23 |
+| [`(constructor)`](bad_expected_access/op_constructor.md) | コンストラクタ | C++23 |
 | `(destructor)` | デストラクタ | C++23 |
-| [`error`](bad_expected_access/error.md.nolink) | エラー値を取得する | C++23 |
-| [`what`](bad_expected_access/what.md.nolink) | エラー理由の文字列を取得する | C++23 |
+| `operator=` | コピー／ムーブ代入演算子 | C++23 |
+| [`error`](bad_expected_access/error.md) | エラー値を取得する | C++23 |
+| [`what`](bad_expected_access/what.md) | エラー理由の文字列を取得する | C++23 |
 
 
 ## 例
diff --git a/reference/expected/bad_expected_access/error.md b/reference/expected/bad_expected_access/error.md
new file mode 100644
index 0000000000..66947a8e76
--- /dev/null
+++ b/reference/expected/bad_expected_access/error.md
@@ -0,0 +1,71 @@
+# error
+* expected[meta header]
+* function[meta id-type]
+* std[meta namespace]
+* bad_expected_access[meta class]
+* cpp23[meta cpp]
+
+```cpp
+constexpr const E& error() const & noexcept;   // (1)
+constexpr E& error() & noexcept;               // (2)
+constexpr const E&& error() const && noexcept; // (3)
+constexpr E&& error() && noexcept;             // (4)
+```
+
+## 概要
+エラー値を取得する。
+
+
+## 戻り値
+動作説明用のメンバ変数として、エラー値を保持する`unex`を導入する。
+
+- (1), (2) : `unex`
+- (3), (4) : [`std::move`](/reference/utility/move.md)`(unex)`
+
+
+## 例外
+投げない
+
+
+## 例
+```cpp example
+#include <cassert>
+#include <expected>
+#include <iostream>
+#include <string>
+
+int main()
+{
+  std::expected<int, std::string> v = std::unexpected{"ERR"};
+  try {
+    std::cout << v.value() << std::endl;
+  } catch (const std::bad_expected_access<std::string>& ex) {
+    std::cout << "throw:" << ex.error() << std::endl;
+  }
+}
+```
+* error()[color ff0000]
+* value()[link ../expected/value.md]
+* std::unexpected[link ../unexpected.md]
+* std::bad_expected_access[link ../bad_expected_access.md]
+
+### 出力
+```
+throw:ERR
+```
+
+
+## バージョン
+### 言語
+- C++23
+
+### 処理系
+- [Clang](/implementation.md#clang): 16.0
+- [GCC](/implementation.md#gcc): 12.1
+- [ICC](/implementation.md#icc): ??
+- [Visual C++](/implementation.md#visual_cpp): ??
+
+
+## 参照
+- [P0323R12 std::expected](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html)
+- [P2549R1 `std::unexpected<E>` should have `error()` as member accessor](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2549r1.html)
diff --git a/reference/expected/bad_expected_access/op_constructor.md b/reference/expected/bad_expected_access/op_constructor.md
new file mode 100644
index 0000000000..4049783bdd
--- /dev/null
+++ b/reference/expected/bad_expected_access/op_constructor.md
@@ -0,0 +1,52 @@
+# コンストラクタ
+* expected[meta header]
+* function[meta id-type]
+* std[meta namespace]
+* bad_expected_access[meta class]
+* cpp23[meta cpp]
+
+```cpp
+explicit bad_expected_access(E e);                // (1)
+bad_expected_access(const bad_expected_access&);  // (2)
+bad_expected_access(bad_expected_access&&);       // (3)
+```
+* bad_expected_access[link ../bad_expected_access.md]
+
+## 概要
+- (1) : エラー値を[`std::move`](/reference/utility/move.md)`(e)`で初期化する。
+- (2) : コピーコンストラクタ。
+- (3) : ムーブコンストラクタ。
+
+
+## 例
+```cpp example
+#include <cassert>
+#include <expected>
+
+int main()
+{
+  std::bad_expected_access<int> ex{42};
+  assert(ex.error() == 42);
+}
+```
+* std::bad_expected_access[color ff0000]
+* error()[link error.md]
+
+### 出力
+```
+```
+
+
+## バージョン
+### 言語
+- C++23
+
+### 処理系
+- [Clang](/implementation.md#clang): 16.0
+- [GCC](/implementation.md#gcc): 12.1
+- [ICC](/implementation.md#icc): ??
+- [Visual C++](/implementation.md#visual_cpp): ??
+
+
+## 参照
+- [P0323R12 std::expected](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html)
diff --git a/reference/expected/bad_expected_access/what.md b/reference/expected/bad_expected_access/what.md
new file mode 100644
index 0000000000..38ad29ef36
--- /dev/null
+++ b/reference/expected/bad_expected_access/what.md
@@ -0,0 +1,64 @@
+# what
+* expected[meta header]
+* function[meta id-type]
+* std[meta namespace]
+* bad_expected_access[meta class]
+* cpp23[meta cpp]
+
+```cpp
+const char* what() const noexcept override;
+```
+
+## 概要
+エラー理由の文字列を取得する。
+
+
+## 戻り値
+エラー理由となる実装定義の文字列
+
+
+## 例外
+投げない
+
+
+## 例
+```cpp example
+#include <cassert>
+#include <expected>
+#include <iostream>
+#include <string>
+
+int main()
+{
+  std::expected<int, std::string> v = std::unexpected{"ERR"};
+  try {
+    std::cout << v.value() << std::endl;
+  } catch (const std::bad_expected_access<std::string>& ex) {
+    std::cout << ex.what() << std::endl;
+  }
+}
+```
+* what()[color ff0000]
+* value()[link ../expected/value.md]
+* std::unexpected[link ../unexpected.md]
+* std::bad_expected_access[link ../bad_expected_access.md]
+
+### 出力例
+```
+bad access to std::expected without expected value
+```
+
+
+## バージョン
+### 言語
+- C++23
+
+### 処理系
+- [Clang](/implementation.md#clang): 16.0
+- [GCC](/implementation.md#gcc): 12.1
+- [ICC](/implementation.md#icc): ??
+- [Visual C++](/implementation.md#visual_cpp): ??
+
+
+## 参照
+- [P0323R12 std::expected](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html)
diff --git a/reference/expected/expected.void/value.md b/reference/expected/expected.void/value.md
index 45e4c49db0..a69e3d1d17 100644
--- a/reference/expected/expected.void/value.md
+++ b/reference/expected/expected.void/value.md
@@ -43,7 +43,7 @@ int main()
 }
 ```
 * value()[color ff0000]
-* error()[link ../bad_expected_access/error.md.nolink]
+* error()[link ../bad_expected_access/error.md]
 * std::unexpected[link ../unexpected.md]
 * std::bad_expected_access[link ../bad_expected_access.md]
 
diff --git a/reference/expected/expected/value.md b/reference/expected/expected/value.md
index 8f1f26ffca..ab4a91004c 100644
--- a/reference/expected/expected/value.md
+++ b/reference/expected/expected/value.md
@@ -48,7 +48,7 @@ int main()
 }
 ```
 * value()[color ff0000]
-* error()[link ../bad_expected_access/error.md.nolink]
+* error()[link ../bad_expected_access/error.md]
 * std::unexpected[link ../unexpected.md]
 * std::bad_expected_access[link ../bad_expected_access.md]
 
diff --git a/reference/expected/unexpected.md b/reference/expected/unexpected.md
index 0ce15ea9cf..e0dc8715d3 100644
--- a/reference/expected/unexpected.md
+++ b/reference/expected/unexpected.md
@@ -12,7 +12,7 @@ namespace std {
 ```
 
 ## 概要
-`unexpected`クラスは、[`std::expected<T, E>`](expected.md)に格納される任意の型`E`の値をエラー値として表現する。
+`unexpected`クラスは、[`std::expected<T, E>`](expected.md)に格納される任意の型`E`のエラー値を表現するヘルパークラスである。
 
 
 ## 適格要件
@@ -39,7 +39,7 @@ namespace std {
 
 | 名前            | 説明           | 対応バージョン |
 |-----------------|----------------|-------|
-| [`error`](unexpected/error.md) | 値を取得する | C++23 |
+| [`error`](unexpected/error.md) | エラー値を取得する | C++23 |
 
 ### 比較
 
diff --git a/reference/expected/unexpected/error.md b/reference/expected/unexpected/error.md
index 054b65f7b3..8a6d6922bf 100644
--- a/reference/expected/unexpected/error.md
+++ b/reference/expected/unexpected/error.md
@@ -13,11 +13,11 @@ constexpr E&& error() && noexcept;             // (4)
 ```
 
 ## 概要
-値を取得する。
+エラー値を取得する。
 
 
 ## 戻り値
-動作説明用のメンバ変数として、値を保持する`unex`を導入する。
+動作説明用のメンバ変数として、エラー値を保持する`unex`を導入する。
 
 - (1), (2) : `unex`
 - (3), (4) : [`std::move`](/reference/utility/move.md)`(unex)`
diff --git a/reference/expected/unexpected/op_constructor.md b/reference/expected/unexpected/op_constructor.md
index 258bd17dc9..763cccae60 100644
--- a/reference/expected/unexpected/op_constructor.md
+++ b/reference/expected/unexpected/op_constructor.md
@@ -38,9 +38,9 @@ constexpr explicit unexpected(in_place_t, initializer_list<U> il, Args&&... args
 
 
 ## 効果
-- (3) : [`std::forward`](/reference/utility/forward.md)`<Err>(e)`で値を直接非リスト初期化する。
-- (4) : [`std::forward`](/reference/utility/forward.md)`<Args>(args)...`で値を直接非リスト初期化する。
-- (5) : `il,` [`std::forward`](/reference/utility/forward.md)`<Args>(args)...`で値を直接非リスト初期化する。
+- (3) : [`std::forward`](/reference/utility/forward.md)`<Err>(e)`でエラー値を直接非リスト初期化する。
+- (4) : [`std::forward`](/reference/utility/forward.md)`<Args>(args)...`でエラー値を直接非リスト初期化する。
+- (5) : `il,` [`std::forward`](/reference/utility/forward.md)`<Args>(args)...`でエラー値を直接非リスト初期化する。
 
 
 ## 例外
@@ -100,7 +100,7 @@ int main()
     std::unexpected<IntTuple> dst{src};
     assert((dst.error() == IntTuple{1, 2}));
   }
-  // (3) 変換構築
+  // (3) 変換ムーブ構築
   {
     UniquePtr src = std::make_unique<int>(42);
     std::unexpected<SharedPtr> dst{std::move(src)};
diff --git a/reference/expected/unexpected/op_deduction_guide.md b/reference/expected/unexpected/op_deduction_guide.md
index dd79e8017a..0927d9d581 100644
--- a/reference/expected/unexpected/op_deduction_guide.md
+++ b/reference/expected/unexpected/op_deduction_guide.md
@@ -12,7 +12,7 @@ namespace std {
 ```
 
 ## 概要
-`std::expected`クラステンプレートの型推論補助。
+`std::unexpected`クラステンプレートの型推論補助。
 
 
 ## 例