From 63454c11aa909eafabe5b91233017da599b40d01 Mon Sep 17 00:00:00 2001
From: Andrzej Krzemienski <akrzemi1@gmail.com>
Date: Thu, 6 Oct 2016 23:17:20 +0200
Subject: [PATCH] unit-tests for optional ref conversion fix

---
 test/optional_test_ref_portable_minimum.cpp | 23 +++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/test/optional_test_ref_portable_minimum.cpp b/test/optional_test_ref_portable_minimum.cpp
index 303559a..c929c3a 100644
--- a/test/optional_test_ref_portable_minimum.cpp
+++ b/test/optional_test_ref_portable_minimum.cpp
@@ -430,6 +430,23 @@ void test_swap()
   BOOST_TEST(boost::addressof(*o2_) == boost::addressof(v1));
 }
 
+template <typename T, typename U>
+void test_convertability_of_compatible_reference_types()
+{
+  typename concrete_type_of<T>::type v1(1);
+  optional<T&> oN, o1(v1);
+  optional<U&> uN(oN), u1(o1);
+  BOOST_TEST(!uN);
+  BOOST_TEST(u1);
+  BOOST_TEST(boost::addressof(*u1) == boost::addressof(*o1));
+  
+  uN = o1;
+  u1 = oN;
+  BOOST_TEST(!u1);
+  BOOST_TEST(uN);
+  BOOST_TEST(boost::addressof(*uN) == boost::addressof(*o1));
+}
+
 template <typename T>
 void test_optional_ref()
 {
@@ -472,5 +489,11 @@ int main()
   test_optional_const_ref<Abstract>();
   test_optional_const_ref< optional<int> >();
   
+  test_convertability_of_compatible_reference_types<int, const int>();
+  test_convertability_of_compatible_reference_types<Impl, Abstract>();
+  test_convertability_of_compatible_reference_types<Impl, const Abstract>();
+  test_convertability_of_compatible_reference_types<const Impl, const Abstract>();
+  test_convertability_of_compatible_reference_types<optional<int>, const optional<int> >();
+  
   return boost::report_errors();
 }