Update test/result_copy_construct

include/boost/system/result.hpp

@@ -487,6 +487,20 @@ public:
     }
 };
 
+template<class Ch, class Tr, class E> std::basic_ostream<Ch, Tr>& operator<<( std::basic_ostream<Ch, Tr>& os, result<void, E> const & r )
+{
+    if( r.has_value() )
+    {
+        os << "value:void";
+    }
+    else
+    {
+        os << "error:" << r.error();
+    }
+
+    return os;
+}
+
 } // namespace system
 } // namespace boost
 

test/result_copy_construct.cpp

@@ -145,5 +145,37 @@ int main()
 
     BOOST_TEST_EQ( X::instances, 0 );
 
+    {
+        result<void> r;
+        result<void> r2( r );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    {
+        result<void> const r;
+        result<void> r2( r );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        result<void> r( ec );
+        result<void> r2( r );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        result<void> const r( ec );
+        result<void> r2( r );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
     return boost::report_errors();
 }