From af3f74de8cada6cc9fe0962164f4aca8393b7774 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Sat, 5 Feb 2022 09:58:30 -0500
Subject: [PATCH] Stop using std::iterator (fixes #618)

Create the typedefs directly in iterators rather than deriving from
the deprecated std::iterator class.
---
 include/qpdf/QPDFNameTreeObjectHelper.hh   | 11 ++++++++---
 include/qpdf/QPDFNumberTreeObjectHelper.hh | 11 ++++++++---
 include/qpdf/QPDFObjectHandle.hh           | 22 ++++++++++++++++------
 libqpdf/qpdf/NNTree.hh                     | 11 ++++++++---
 4 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/include/qpdf/QPDFNameTreeObjectHelper.hh b/include/qpdf/QPDFNameTreeObjectHelper.hh
index ea395c6a..baa6e5e9 100644
--- a/include/qpdf/QPDFNameTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNameTreeObjectHelper.hh
@@ -77,12 +77,17 @@ class QPDFNameTreeObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     bool findObject(std::string const& utf8, QPDFObjectHandle& oh);
 
-    class iterator: public std::iterator<
-        std::bidirectional_iterator_tag,
-        std::pair<std::string, QPDFObjectHandle>>
+    class iterator
     {
         friend class QPDFNameTreeObjectHelper;
       public:
+        typedef std::pair<std::string, QPDFObjectHandle> T;
+        using iterator_category = std::bidirectional_iterator_tag;
+        using value_type = T;
+        using difference_type = long;
+        using pointer = T*;
+        using reference = T&;
+
         virtual ~iterator() = default;
         QPDF_DLL
         bool valid() const;
diff --git a/include/qpdf/QPDFNumberTreeObjectHelper.hh b/include/qpdf/QPDFNumberTreeObjectHelper.hh
index 4a7bfec0..cfe20b72 100644
--- a/include/qpdf/QPDFNumberTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNumberTreeObjectHelper.hh
@@ -96,12 +96,17 @@ class QPDFNumberTreeObjectHelper: public QPDFObjectHelper
     bool findObjectAtOrBelow(numtree_number idx, QPDFObjectHandle& oh,
                              numtree_number& offset);
 
-    class iterator: public std::iterator<
-        std::bidirectional_iterator_tag,
-        std::pair<numtree_number, QPDFObjectHandle>>
+    class iterator
     {
         friend class QPDFNumberTreeObjectHelper;
       public:
+        typedef std::pair<numtree_number, QPDFObjectHandle> T;
+        using iterator_category = std::bidirectional_iterator_tag;
+        using value_type = T;
+        using difference_type = long;
+        using pointer = T*;
+        using reference = T&;
+
         virtual ~iterator() = default;
         QPDF_DLL
         bool valid() const;
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index 03d7cb0d..262a84b8 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -1479,12 +1479,17 @@ class QPDFObjectHandle::QPDFDictItems
     QPDF_DLL
     QPDFDictItems(QPDFObjectHandle const& oh);
 
-    class iterator: public std::iterator<
-        std::bidirectional_iterator_tag,
-        std::pair<std::string, QPDFObjectHandle>>
+    class iterator
     {
         friend class QPDFDictItems;
       public:
+        typedef std::pair<std::string, QPDFObjectHandle> T;
+        using iterator_category = std::bidirectional_iterator_tag;
+        using value_type = T;
+        using difference_type = long;
+        using pointer = T*;
+        using reference = T&;
+
         QPDF_DLL
         virtual ~iterator() = default;
         QPDF_DLL
@@ -1569,12 +1574,17 @@ class QPDFObjectHandle::QPDFArrayItems
     QPDF_DLL
     QPDFArrayItems(QPDFObjectHandle const& oh);
 
-    class iterator: public std::iterator<
-        std::bidirectional_iterator_tag,
-        QPDFObjectHandle>
+    class iterator
     {
         friend class QPDFArrayItems;
       public:
+        typedef QPDFObjectHandle T;
+        using iterator_category = std::bidirectional_iterator_tag;
+        using value_type = T;
+        using difference_type = long;
+        using pointer = T*;
+        using reference = T&;
+
         QPDF_DLL
         virtual ~iterator() = default;
         QPDF_DLL
diff --git a/libqpdf/qpdf/NNTree.hh b/libqpdf/qpdf/NNTree.hh
index f4472662..f9acc0d1 100644
--- a/libqpdf/qpdf/NNTree.hh
+++ b/libqpdf/qpdf/NNTree.hh
@@ -17,12 +17,17 @@ class NNTreeDetails
 };
 
 class NNTreeImpl;
-class NNTreeIterator: public std::iterator<
-    std::bidirectional_iterator_tag,
-    std::pair<QPDFObjectHandle, QPDFObjectHandle>>
+class NNTreeIterator
 {
     friend class NNTreeImpl;
   public:
+    typedef std::pair<QPDFObjectHandle, QPDFObjectHandle> T;
+    using iterator_category = std::bidirectional_iterator_tag;
+    using value_type = T;
+    using difference_type = long;
+    using pointer = T*;
+    using reference = T&;
+
     virtual ~NNTreeIterator() = default;
     bool valid() const;
     NNTreeIterator& operator++();