Add throwing copy/move/convert tests

test/variant_move_construct_throw.cpp

@@ -0,0 +1,65 @@
+
+// Copyright 2019 Peter Dimov
+//
+// 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
+
+#include <boost/variant2/variant.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <stdexcept>
+
+using namespace boost::variant2;
+
+struct X
+{
+    static int instances;
+
+    X()
+    {
+        ++instances;
+    }
+
+    X( X const& )
+    {
+        throw std::runtime_error( "X(X const&)" );
+    }
+
+    ~X()
+    {
+        --instances;
+    }
+};
+
+int X::instances = 0;
+
+void test()
+{
+    X::instances = 0;
+
+    {
+        variant<X> v1;
+
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        try
+        {
+            variant<X> v2( std::move( v1 ) );
+            BOOST_TEST_EQ( X::instances, 2 );
+        }
+        catch( std::exception const& )
+        {
+        }
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+}
+
+int main()
+{
+    test();
+    return boost::report_errors();
+}