add boost on mac

macx64/include/boost/poly_collection/detail/auto_iterator.hpp

@@ -0,0 +1,56 @@
+/* Copyright 2016 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)
+ *
+ * See http://www.boost.org/libs/poly_collection for library home page.
+ */
+
+#ifndef BOOST_POLY_COLLECTION_DETAIL_AUTO_ITERATOR_HPP
+#define BOOST_POLY_COLLECTION_DETAIL_AUTO_ITERATOR_HPP
+
+#if defined(_MSC_VER)
+#pragma once
+#endif
+
+#include <boost/iterator/iterator_adaptor.hpp>
+
+namespace boost{
+
+namespace poly_collection{
+
+namespace detail{
+
+/* auto_iterator<Iterator> (for want of a better name) behaves like Iterator
+ * save for the fact that it derefs to Iterator& rather than
+ * Iterator::reference. This is useful to "lift" std algorithms so that
+ * user-defined predicates are passed iterators that can then be dereferenced
+ * internally.
+ */
+
+template<typename Iterator>
+class auto_iterator:
+  public boost::iterator_adaptor<auto_iterator<Iterator>,Iterator,Iterator>
+{
+public:
+  auto_iterator()=default;
+  auto_iterator(const Iterator& it):auto_iterator::iterator_adaptor_{it}{}
+  auto_iterator(const auto_iterator&)=default;
+  auto_iterator& operator=(const auto_iterator&)=default;
+
+private:
+  friend class boost::iterator_core_access;
+
+  Iterator& dereference()const noexcept
+  {
+    return const_cast<auto_iterator*>(this)->base_reference();
+  }
+};
+
+} /* namespace poly_collection::detail */
+
+} /* namespace poly_collection */
+
+} /* namespace boost */
+
+#endif