title: How to add a interceptor using librdkafka C++ client?
body: <p>I am trying to write a Kafka producer using librdkafka C++ client, I found there is no API to add a custom interceptor in C++ version, while i found some function to add interceptor in C  which are not exposed in C++ client like</p>
  <pre class="lang-c prettyprint-override"><code>rd_kafka_resp_err_t
  rd_kafka_interceptor_add_on_send (
          rd_kafka_t *rk, const char *ic_name,
          rd_kafka_interceptor_f_on_send_t *on_send,
          void *ic_opaque)
  </code></pre>