1 files changed, 59 insertions, 0 deletions
diff --git a/boost-ublas-c++20-iterator.patch b/boost-ublas-c++20-iterator.patch
new file mode 100644
index 000000000000..21321cc37f58
--- /dev/null
+++ b/boost-ublas-c++20-iterator.patch
@@ -0,0 +1,59 @@
+From a31e5cffa85f58b64a39fa7c4a1bd3bd9228b069 Mon Sep 17 00:00:00 2001
+From: Conrad Poelman <cpgithub@stellarscience.com>
+Date: Tue, 4 Aug 2020 17:20:40 -0400
+Subject: [PATCH] Remove deprecated inheritance from std::iterator (#97)
+
+std::iterator was deprecated in C++17 and removed in C++20. I replaced the inheritance with the 5 equivalent typedefs, even though they're not all used by ublas, for compatibility in case clients depend on them.
+---
+ .../boost/numeric/ublas/detail/iterator.hpp   | 24 ++++++++++++++-----
+ 1 file changed, 18 insertions(+), 6 deletions(-)
+
+diff --git a/include/boost/numeric/ublas/detail/iterator.hpp b/include/boost/numeric/ublas/detail/iterator.hpp
+index 1723a301c..7aebf2f9f 100644
+--- a/include/boost/numeric/ublas/detail/iterator.hpp
++++ b/include/boost/numeric/ublas/detail/iterator.hpp
+@@ -107,8 +107,12 @@ namespace boost { namespace numeric { namespace ublas {
+    * via the post increment operator.
+    */
+     template<class IC, class I, class T>
+-    struct forward_iterator_base:
+-        public std::iterator<IC, T> {
++    struct forward_iterator_base {
++        typedef IC iterator_category;
++        typedef T value_type;
++        typedef std::ptrdiff_t difference_type;
++        typedef T* pointer;
++        typedef T& reference;
+         typedef I derived_iterator_type;
+         typedef T derived_value_type;
+ 
+@@ -145,8 +149,12 @@ namespace boost { namespace numeric { namespace ublas {
+    * via the post increment and post decrement operator.
+    */
+     template<class IC, class I, class T>
+-    struct bidirectional_iterator_base:
+-        public std::iterator<IC, T> {
++    struct bidirectional_iterator_base {
++        typedef IC iterator_category;
++        typedef T value_type;
++        typedef std::ptrdiff_t difference_type;
++        typedef T* pointer;
++        typedef T& reference;
+         typedef I derived_iterator_type;
+         typedef T derived_value_type;
+ 
+@@ -200,8 +208,12 @@ namespace boost { namespace numeric { namespace ublas {
+    */
+     template<class IC, class I, class T, class D = std::ptrdiff_t>
+     // ISSUE the default for D seems rather dangerous as it can easily be (silently) incorrect
+-    struct random_access_iterator_base:
+-        public std::iterator<IC, T> {
++    struct random_access_iterator_base {
++        typedef IC iterator_category;
++        typedef T value_type;
++        typedef D difference_type;
++        typedef T* pointer;
++        typedef T& reference;
+         typedef I derived_iterator_type;
+         typedef T derived_value_type;
+         typedef D derived_difference_type;