solved issue #20

doc/poly_collection.qbk

@@ -1,7 +1,7 @@
 [library Boost.PolyCollection
   [quickbook 1.6]
   [authors [López Muñoz, Joaquín M]]
-  [copyright 2016-2020 Joaquín M López Muñoz]
+  [copyright 2016-2021 Joaquín M López Muñoz]
   [category containers]
   [id poly_collection]
   [dirname poly_collection]
@@ -1122,6 +1122,13 @@ to allow for the definition of container-level `operator<` and related operators
 
 [section Release notes]
 
+[section Boost 1.76]
+
+* Worked around [@https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95888 GCC bug] affecting
+GCC versions 9.3-10.2 (issue [github poly_collection 20]).
+
+[endsect]
+
 [section Boost 1.74]
 
 * Fixed internal ambiguity problem between `boost::type_erasure::any` and

include/boost/poly_collection/detail/iterator_impl.hpp

@@ -1,4 +1,4 @@
-/* Copyright 2016-2017 Joaquin M Lopez Munoz.
+/* Copyright 2016-2021 Joaquin M Lopez Munoz.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -13,6 +13,7 @@
 #pragma once
 #endif
 
+#include <boost/detail/workaround.hpp>
 #include <boost/iterator/iterator_adaptor.hpp>
 #include <boost/iterator/iterator_facade.hpp>
 #include <boost/poly_collection/detail/is_constructible.hpp>
@@ -143,6 +144,15 @@ class local_iterator_impl:
   using const_segment_map_iterator=
     typename PolyCollection::const_segment_map_iterator;
 
+#if BOOST_WORKAROUND(BOOST_GCC_VERSION,>=90300)&&\
+    BOOST_WORKAROUND(BOOST_GCC_VERSION,<110000)
+/* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95888 */
+
+public:
+#else
+private:
+#endif
+
   template<typename Iterator>
   local_iterator_impl(
     const_segment_map_iterator mapit,
@@ -232,7 +242,6 @@ struct poly_collection_of<local_iterator_impl<PolyCollection,BaseIterator>>
   using type=PolyCollection;
 };
 
-
 } /* namespace poly_collection::detail */
 
 } /* namespace poly_collection */