P2259R1対応 counted_iterator::operator->追加

reference/iterator/counted_iterator.md

@@ -49,7 +49,7 @@ namespace std {
 | [`base`](counted_iterator/base.md)          | 元のイテレータを取得する | C++20 |
 | [`count`](counted_iterator/count.md)          | 代入演算子 | C++20 |
 | [`operator*`](counted_iterator/op_deref.md)           | 間接参照演算子 | C++20 |
-| [`operator->`](counted_iterator/op_arrow.md.nolink)          | メンバアクセス演算子 | C++20 |
+| [`operator->`](counted_iterator/op_arrow.md)          | メンバアクセス演算子 | C++20 |
 | [`operator++`](counted_iterator/op_increment.md)      | イテレータをインクリメントする | C++20 |
 | [`operator--`](counted_iterator/op_decrement.md)      | イテレータをデクリメントする | C++20 |
 | [`operator+`](counted_iterator/op_plus.md)      | イテレータを進める | C++20 |

reference/iterator/counted_iterator/op_arrow.md

@@ -0,0 +1,74 @@
+# operator->
+* iterator[meta header]
+* std[meta namespace]
+* counted_iterator[meta class]
+* function[meta id-type]
+* cpp20[meta cpp]
+
+```cpp
+constexpr auto operator->() const noexcept
+  requires contiguous_iterator<I>;
+```
+* contiguous_iterator[link /reference/iterator/contiguous_iterator.md]
+
+## 概要
+イテレータを通して参照先の要素のメンバにアクセスする
+
+## 効果
+
+`I`の値を`current`メンバ変数に保持するとして、以下と等価
+
+```cpp
+return to_address(current);
+```
+* to_address[link /reference/memory/to_address.md]
+
+## 例
+```cpp example
+#include <iostream>
+#include <iterator>
+#include <ranges>
+#include <vector>
+
+struct S {
+  int n;
+
+  S(int a) : n{a} {}
+
+  void print() const {
+    std::cout << this->n << '\n';
+  }
+};
+
+int main() {
+  std::vector<S> vec = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+  std::counted_iterator ci{std::ranges::begin(vec), 5};
+
+  ci->print();
+
+  ++ci;
+
+  ci->print();
+}
+```
+* ci->[color ff0000]
+* ranges::begin[link /reference/ranges/begin.md]
+
+### 出力
+```
+1
+2
+```
+
+## バージョン
+### 言語
+- C++20
+
+### 処理系
+- [Clang](/implementation.md#clang): ??
+- [GCC](/implementation.md#gcc): 12.0
+- [Visual C++](/implementation.md#visual_cpp): 2022
+
+## 参照
+- [P2259R1 Repairing input range adaptors and `counted_iterator`](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2259r1.html)