Changed the void output functions to return bool for success or failure.

Author: JonathanHenson

include/aws/crt/mqtt/MqttClient.h

@@ -104,25 +104,25 @@ namespace Aws
                 /**
                  * Sets LastWill for the connection. The memory backing payload must outlive the connection.
                  */
-                void SetWill(const char* topic, QOS qos, bool retain,
+                bool SetWill(const char* topic, QOS qos, bool retain,
                         const ByteBuf& payload) noexcept;
 
                 /**
                  * Sets login credentials for the connection. The must get set before the Connect call
                  * if it is to be used. 
                  */
-                void SetLogin(const char* userName, const char* password) noexcept;
+                bool SetLogin(const char* userName, const char* password) noexcept;
 
                 /**
                  * Initiates the connection, OnConnectionFailedHandler and/or OnConnAckHandler will
                  * be invoked in an event-loop thread.
                  */
-                void Connect(const char* clientId, bool cleanSession, uint16_t keepAliveTime) noexcept;
+                bool Connect(const char* clientId, bool cleanSession, uint16_t keepAliveTime) noexcept;
 
                 /**
                  * Initiates disconnect, OnDisconnectHandler will be invoked in an event-loop thread.
                  */
-                void Disconnect() noexcept;
+                bool Disconnect() noexcept;
 
                 /**
                  * Subcribes to topicFilter. OnPublishRecievedHandler will be invoked from an event-loop
@@ -185,7 +185,6 @@ namespace Aws
             class AWS_CRT_CPP_API MqttClient final
             {
                 friend class MqttConnection;
-
             public:
                 /**
                  * Initialize an MqttClient using bootstrap and allocator

samples/mqtt_pub_sub/main.cpp

@@ -242,7 +242,13 @@ int main(int argc, char* argv[])
     /*
      * Actually perform the connect dance.
      */
-    connection.Connect("client_id12335456", true, 0);
+    if (!connection.Connect("client_id12335456", true, 0))
+    {
+        fprintf(stderr, "MQTT Connection failed with error %s\n",
+            ErrorDebugString(connection.LastError()));
+        exit(-1);
+    }
+
     std::unique_lock<std::mutex> uniqueLock(mutex);
     conditionVariable.wait(uniqueLock, [&]() {return connectionSucceeded || connectionClosed; });
 

source/mqtt/MqttClient.cpp

@@ -224,7 +224,7 @@ namespace Aws
                 return m_lastError;
             }
 
-            void MqttConnection::SetWill(const char* topic, QOS qos, bool retain,
+            bool MqttConnection::SetWill(const char* topic, QOS qos, bool retain,
                          const ByteBuf& payload) noexcept
             {
                 ByteBuf topicBuf = aws_byte_buf_from_c_str(topic);
@@ -234,10 +234,13 @@ namespace Aws
                 if (aws_mqtt_client_connection_set_will(m_underlyingConnection, &topicCur, qos, retain, &payloadCur))
                 {
                     m_lastError = aws_last_error();
+                    return false;
                 }
+
+                return true;
             }
 
-            void MqttConnection::SetLogin(const char* userName, const char* password) noexcept
+            bool MqttConnection::SetLogin(const char* userName, const char* password) noexcept
             {
                 ByteBuf userNameBuf = aws_byte_buf_from_c_str(userName);
                 ByteCursor userNameCur = aws_byte_cursor_from_buf(&userNameBuf);
@@ -246,10 +249,13 @@ namespace Aws
                 if (aws_mqtt_client_connection_set_login(m_underlyingConnection, &userNameCur, &pwdCur))
                 {
                     m_lastError = aws_last_error();
+                    return false;
                 }
+
+                return true;
             }
 
-            void MqttConnection::Connect(const char* clientId, bool cleanSession,
+            bool MqttConnection::Connect(const char* clientId, bool cleanSession,
                     uint16_t keepAliveTime) noexcept
             {
                 ByteBuf clientIdBuf = aws_byte_buf_from_c_str(clientId);
@@ -259,19 +265,21 @@ namespace Aws
                         &clientIdCur, cleanSession, keepAliveTime))
                 {
                     m_lastError = aws_last_error();
+                    return false;
                 }
-                else
-                {
-                    m_connectionState = ConnectionState::Connecting;
-                }
+                m_connectionState = ConnectionState::Connecting;
+                return true;             
             }
 
-            void MqttConnection::Disconnect() noexcept
+            bool MqttConnection::Disconnect() noexcept
             {
                 if (aws_mqtt_client_connection_disconnect(m_underlyingConnection))
                 {
                     m_lastError = aws_last_error();
+                    return false;
                 }
+
+                return true;
             }
 
             uint16_t MqttConnection::Subscribe(const char* topicFilter, QOS qos,