fix nullptr construction

Author: BewareMyPower

lib/ConsumerImpl.cc

@@ -1313,7 +1313,7 @@ void ConsumerImpl::negativeAcknowledge(const MessageId& messageId) {
     negativeAcksTracker_->add(messageId);
 }
 
-void ConsumerImpl::disconnectConsumer() { disconnectConsumer(nullptr); }
+void ConsumerImpl::disconnectConsumer() { disconnectConsumer(optional<std::string>{}); }
 
 void ConsumerImpl::disconnectConsumer(const optional<std::string>& assignedBrokerUrl) {
     LOG_INFO("Broker notification of Closed consumer: "

lib/HandlerBase.cc

@@ -85,7 +85,7 @@ void HandlerBase::setCnx(const ClientConnectionPtr& cnx) {
     connection_ = cnx;
 }
 
-void HandlerBase::grabCnx() { grabCnx(nullptr); }
+void HandlerBase::grabCnx() { grabCnx(optional<std::string>{}); }
 
 Future<Result, ClientConnectionPtr> HandlerBase::getConnection(
     const ClientImplPtr& client, const optional<std::string>& assignedBrokerUrl) {
@@ -176,7 +176,7 @@ void HandlerBase::handleDisconnection(Result result, const ClientConnectionPtr&
             break;
     }
 }
-void HandlerBase::scheduleReconnection() { scheduleReconnection(nullptr); }
+void HandlerBase::scheduleReconnection() { scheduleReconnection(optional<std::string>{}); }
 void HandlerBase::scheduleReconnection(const optional<std::string>& assignedBrokerUrl) {
     const auto state = state_.load();
 

lib/ProducerImpl.cc

@@ -981,7 +981,7 @@ void ProducerImpl::disconnectProducer(const optional<std::string>& assignedBroke
     scheduleReconnection(assignedBrokerUrl);
 }
 
-void ProducerImpl::disconnectProducer() { disconnectProducer(nullptr); }
+void ProducerImpl::disconnectProducer() { disconnectProducer(optional<std::string>{}); }
 
 void ProducerImpl::start() {
     HandlerBase::start();