define iterators without std::iterator<>

[ceph.git] / patches / 0019-define-iterators-without-std-iterator.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Thomas Lamprecht <t.lamprecht@proxmox.com>
Date: Wed, 3 May 2023 13:25:08 +0200
Subject: [PATCH] define iterators without std::iterator<>

> std::iterator<> is deprecated in C++17, so let's just
> define the required traits directly.

cherry-picked/backported from upstream PRs:
https://github.com/ceph/ceph/pull/45419/commits
https://github.com/ceph/ceph/pull/45198/commits

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
 .../btree/string_kv_node_layout.h             | 27 +++++++++++--------
 src/include/rados/librados.hpp           |  7 ++++-
 src/include/xlist.h                      | 15 +++++++++--
 3 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/src/crimson/os/seastore/omap_manager/btree/string_kv_node_layout.h b/src/crimson/os/seastore/omap_manager/btree/string_kv_node_layout.h
index 9948a4292..1bd95415a 100644
--- a/src/crimson/os/seastore/omap_manager/btree/string_kv_node_layout.h
+++ b/src/crimson/os/seastore/omap_manager/btree/string_kv_node_layout.h
@@ -294,7 +294,7 @@ class StringKVInnerNodeLayout {
   friend class delta_inner_t;
 public:
   template <bool is_const>
-  class iter_t : public std::iterator<std::input_iterator_tag, StringKVInnerNodeLayout> {
+  class iter_t {
     friend class StringKVInnerNodeLayout;
 
     template <typename iterator, typename const_iterator>
@@ -312,17 +312,22 @@ public:
       uint16_t index) : node(parent), index(index) {}
 
   public:
-    iter_t(const iter_t &) = default;
-    iter_t(iter_t &&) = default;
-    iter_t &operator=(const iter_t &) = default;
-    iter_t &operator=(iter_t &&) = default;
-
-    operator iter_t<!is_const>() const {
-      static_assert(!is_const);
-      return iter_t<!is_const>(node, index);
-    }
-
+    using iterator_category = std::input_iterator_tag;
+    using value_type = StringKVInnerNodeLayout;
+    using difference_type = std::ptrdiff_t;
+    using pointer = StringKVInnerNodeLayout*;
     using reference = iter_t&;
+
+    iter_t(const iter_t &) = default;
+    iter_t(iter_t &&) = default;
+    iter_t &operator=(const iter_t &) = default;
+    iter_t &operator=(iter_t &&) = default;
+
+    operator iter_t<!is_const>() const {
+      static_assert(!is_const);
+      return iter_t<!is_const>(node, index);
+    }
+
     iter_t &operator*() { return *this; }
     iter_t *operator->() { return this; }
 
diff --git a/src/include/rados/librados.hpp b/src/include/rados/librados.hpp
index b40d7bf9a..712a5da82 100644
--- a/src/include/rados/librados.hpp
+++ b/src/include/rados/librados.hpp
@@ -104,8 +104,13 @@ inline namespace v14_2_0 {
   };
   CEPH_RADOS_API std::ostream& operator<<(std::ostream& os, const librados::ObjectCursor& oc);
 
-  class CEPH_RADOS_API NObjectIterator : public std::iterator <std::forward_iterator_tag, ListObject> {
+  class CEPH_RADOS_API NObjectIterator {
   public:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = ListObject;
+    using difference_type = std::ptrdiff_t;
+    using pointer = ListObject*;
+    using reference = ListObject&;
     static const NObjectIterator __EndObjectIterator;
     NObjectIterator(): impl(NULL) {}
     ~NObjectIterator();
diff --git a/src/include/xlist.h b/src/include/xlist.h
index 733a318a9..73e6d8d53 100644
--- a/src/include/xlist.h
+++ b/src/include/xlist.h
@@ -159,10 +159,15 @@ public:
     remove(_back);
   }
 
-  class iterator: std::iterator<std::forward_iterator_tag, T> {
+  class iterator {
   private:
     item *cur;
   public:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = T;
+    using difference_type = std::ptrdiff_t;
+    using pointer = T*;
+    using reference = T&;
     iterator(item *i = 0) : cur(i) {}
     T operator*() { return static_cast<T>(cur->_item); }
     iterator& operator++() {
@@ -183,10 +188,16 @@ public:
   iterator begin() { return iterator(_front); }
   iterator end() { return iterator(NULL); }
 
-  class const_iterator: std::iterator<std::forward_iterator_tag, T> {
+  class const_iterator {
   private:
     item *cur;
   public:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = T;
+    using difference_type = std::ptrdiff_t;
+    using pointer = const T*;
+    using reference = const T&;
+
     const_iterator(item *i = 0) : cur(i) {}
     const T operator*() { return static_cast<const T>(cur->_item); }
     const_iterator& operator++() {