From 8ed3e8c79b5cbccfeccee865e555b68025ee2c1f Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Mon, 25 Jan 2021 08:05:43 -0500
Subject: NNTree: rework iterators to be more memory efficient

Keep a std::pair internal to the iterators so that operator* can
return a reference and operator-> can work, and each can work without
copying pairs of objects around.
---
 libqpdf/qpdf/NNTree.hh | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'libqpdf/qpdf')

diff --git a/libqpdf/qpdf/NNTree.hh b/libqpdf/qpdf/NNTree.hh
index e8360df1..4a843a73 100644
--- a/libqpdf/qpdf/NNTree.hh
+++ b/libqpdf/qpdf/NNTree.hh
@@ -6,6 +6,7 @@
 
 #include <iterator>
 #include <list>
+#include <memory>
 
 class NNTreeDetails
 {
@@ -18,9 +19,6 @@ class NNTreeDetails
 class NNTreeImpl;
 class NNTreeIterator: public std::iterator<
     std::bidirectional_iterator_tag,
-    std::pair<QPDFObjectHandle, QPDFObjectHandle>,
-    void,
-    std::pair<QPDFObjectHandle, QPDFObjectHandle>*,
     std::pair<QPDFObjectHandle, QPDFObjectHandle>>
 {
     friend class NNTreeImpl;
@@ -41,6 +39,7 @@ class NNTreeIterator: public std::iterator<
         return t;
     }
     reference operator*();
+    pointer operator->();
     bool operator==(NNTreeIterator const& other) const;
     bool operator!=(NNTreeIterator const& other) const
     {
@@ -63,6 +62,7 @@ class NNTreeIterator: public std::iterator<
 
     // ABI: for qpdf 11, make qpdf a reference
     NNTreeIterator(NNTreeImpl& impl);
+    void updateIValue(bool allow_invalid = true);
     bool deepen(QPDFObjectHandle node, bool first, bool allow_empty);
     void setItemNumber(QPDFObjectHandle const& node, int);
     void addPathElement(QPDFObjectHandle const& node, int kid_number);
@@ -79,6 +79,7 @@ class NNTreeIterator: public std::iterator<
     std::list<PathElement> path;
     QPDFObjectHandle node;
     int item_number;
+    value_type ivalue;
 };
 
 class NNTreeImpl
-- 
cgit v1.2.3-70-g09d2