Add default constructor to Topic

include/cppkafka/topic.h

@@ -51,6 +51,14 @@ public:
      */
     static Topic make_non_owning(rd_kafka_topic_t* handle);
 
+    /**
+     * \brief Constructs an empty topic
+     *
+     * Note that using any methods except Topic::get_handle on an empty topic is undefined 
+     * behavior
+     */
+    Topic();
+
     /**
      * \brief Constructs a topic using a handle
      *

src/topic.cpp

@@ -42,6 +42,11 @@ Topic Topic::make_non_owning(rd_kafka_topic_t* handle) {
     return Topic(handle, NonOwningTag{});
 }
 
+Topic::Topic() 
+: handle_(nullptr, nullptr) {
+
+}
+
 Topic::Topic(rd_kafka_topic_t* handle) 
 : handle_(handle, &rd_kafka_topic_destroy) {