tests: added two test cases from GitHub issues

test/Jamfile.v2

@@ -18,6 +18,7 @@ import testing ;
 {
   test-suite optional :
     [ run optional_test.cpp ]
+    [ run optional_test_assign.cpp ]
     [ run optional_test_swap.cpp ]
     [ run optional_test_conversions_from_U.cpp ]
     [ run optional_test_convert_from_T.cpp ]

test/optional_test_assign.cpp

@@ -0,0 +1,30 @@
+// Copyright (C) 2018 Andrzej Krzemienski.
+//
+// Use, modification, and distribution is subject to 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/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  akrzemi1@gmail.com
+
+#include "boost/core/lightweight_test.hpp"
+#include "boost/optional/optional.hpp"
+
+void test_assignment_to_empty()
+{
+  // this test used to fail on GCC 8.1.0/8.2.0/9.0.0 with -std=c++98
+  boost::optional<int> oa, ob(1);
+  BOOST_TEST(!oa);
+  BOOST_TEST(ob);
+
+  oa = ob;
+  BOOST_TEST(oa);
+}
+
+int main()
+{
+  test_assignment_to_empty();
+  return boost::report_errors();
+}

test/optional_test_deleted_default_ctor.cpp

@@ -1,4 +1,6 @@
 // Copyright 2017 Peter Dimov
+// Copyright 2017 Vinnie NotDefaultConstructible
+// Copyright 2018 Andrzej Krzemienski
 //
 // Distributed under the Boost Software License, Version 1.0.
 //
@@ -19,8 +21,8 @@ int main()
 
 class basic_multi_buffer;
 
-class const_buffers_type
+class const_buffers_type // a similar declaration in boost.beast had problem
-{
+{                        // with boost opitonal
     basic_multi_buffer const* b_;
 
     friend class basic_multi_buffer;
@@ -29,16 +31,36 @@ class const_buffers_type
     const_buffers_type(basic_multi_buffer const& b);
 
 public:
-
     const_buffers_type() = delete;
     const_buffers_type(const_buffers_type const&) = default;
     const_buffers_type& operator=(const_buffers_type const&) = default;
 };
 
+void test_beast_example()
+{
+  // test if it even compiles
+  boost::optional< std::pair<const_buffers_type, int> > opt, opt2;
+  opt = opt2;
+  (void)opt;
+}
+
+struct NotDefaultConstructible // minimal class exposing the problem
+{
+  NotDefaultConstructible() = delete;
+};
+
+void test_assign_for_non_default_constructible()
+{
+  // test if it even compiles
+  boost::optional<NotDefaultConstructible> opt, opt2;
+  opt = opt2;
+  (void)opt;
+}
+
 int main()
 {
-    boost::optional< std::pair<const_buffers_type, int> > opt, opt2;
+  test_beast_example();
-    opt = opt2;
+  test_assign_for_non_default_constructible();
 }
 
 #endif