Add initial consumer code

src/topic_partition.cpp

@@ -0,0 +1,35 @@
+#include <librdkafka/rdkafka.h>
+#include "topic_partition.h"
+
+using std::string;
+
+namespace cppkafka {
+
+TopicPartition::TopicPartition(const string& topic) 
+: TopicPartition(topic, RD_KAFKA_PARTITION_UA) {
+
+}
+
+TopicPartition::TopicPartition(const string& topic, int partition) 
+: TopicPartition(topic, partition, RD_KAFKA_OFFSET_INVALID) {
+
+}
+
+TopicPartition::TopicPartition(const string& topic, int partition, int64_t offset) 
+: topic_(topic), partition_(partition), offset_(offset) {
+
+}
+
+const string& TopicPartition::get_topic() const {
+    return topic_;
+}
+
+int TopicPartition::get_partition() const {
+    return partition_;
+}
+
+int64_t TopicPartition::get_offset() const {
+    return offset_;
+}
+
+} // cppkafka