Address various RemoteTools PR feedback items

Signed-off-by: puvvadar <[email protected]>

Code/Framework/AzFramework/AzFramework/Application/Application.cpp

@@ -228,7 +228,7 @@ namespace AzFramework
                 using AssetCatalogBus = AZ::Data::AssetCatalogRequestBus;
                 AssetCatalogBus::Broadcast(AZStd::move(StartMonitoringAssetsAndLoadCatalog));
             }
-#if !defined(_RELEASE)
+#if defined(ENABLE_REMOTE_TOOLS)
             IRemoteTools* remoteTools = RemoteToolsInterface::Get();
             if (remoteTools)
             {

Code/Framework/AzFramework/AzFramework/Network/IRemoteTools.h

@@ -16,11 +16,16 @@
 #include <AzCore/RTTI/RTTI.h>
 #include <AzCore/Serialization/SerializeContext.h>
 #include <AzCore/std/containers/deque.h>
+#include <AzCore/std/containers/span.h>
 #include <AzCore/std/containers/unordered_map.h>
 #include <AzCore/std/smart_ptr/intrusive_ptr.h>
 #include <AzCore/std/smart_ptr/intrusive_refcount.h>
 #include <AzCore/std/string/string.h>
 
+#if !defined(_RELEASE)
+    #define ENABLE_REMOTE_TOOLS 1
+#endif
+
 namespace AZ
 {
     template<typename T>
@@ -37,24 +42,8 @@ namespace AzFramework
         AZ_CLASS_ALLOCATOR(RemoteToolsMessage, AZ::OSAllocator, 0);
         AZ_RTTI(RemoteToolsMessage, "{8512328C-949D-4F0C-B48D-77C26C207443}");
 
-        RemoteToolsMessage()
-            : m_msgId(0)
-            , m_senderTargetId(0)
-            , m_customBlob(nullptr)
-            , m_customBlobSize(0)
-            , m_isBlobOwner(false)
-            , m_immediateSelfDispatch(false)
-        {
-        }
-        RemoteToolsMessage(AZ::u64 msgId)
-            : m_msgId(msgId)
-            , m_senderTargetId(0)
-            , m_customBlob(nullptr)
-            , m_customBlobSize(0)
-            , m_isBlobOwner(false)
-            , m_immediateSelfDispatch(false)
-        {
-        }
+        RemoteToolsMessage() = default;
+        explicit RemoteToolsMessage(AZ::u64 msgId) : m_msgId(msgId) {}
 
         virtual ~RemoteToolsMessage();
 
@@ -64,17 +53,14 @@ namespace AzFramework
         //! @param ownBlob Whether this message owns the life cycle of the blob memory
         void AddCustomBlob(const void* blob, size_t blobSize, bool ownBlob = false);
 
-        //! Sets if this message can be immediately dispatched if the receipient is itself
-        //! @param immediateSelfDispatchEnabled Whether this message can be immediately dispatched
-        void SetImmediateSelfDispatchEnabled(bool immediateSelfDispatchEnabled);
-
-        //! Gets if this message can be immediately dispatched if the receipient is itself
-        //! @return Whether this message can be immediately dispatched
-        bool IsImmediateSelfDispatchEnabled() const;
+        //! Add a custom data blob to a Remote Tools message
+        //! @param blob Span of byte representing the blob
+        //! @param ownBlob Whether this message owns the life cycle of the blob memory
+        void AddCustomBlob(AZStd::span<AZStd::byte const> blob, bool ownBlob = false);
 
-        //! Gets the custom data blob assosciated with this message
+        //! Gets the custom data blob associated with this message
         //! @return Memory address of the start of the blob or nullptr if there is none
-        const void* GetCustomBlob() const;
+        const AZStd::span<AZStd::byte const> GetCustomBlob() const;
 
         //! Gets the size of the custom data blob associated with this message
         //! @return Size of the data blob or 0 if there is none
@@ -101,19 +87,19 @@ namespace AzFramework
         static void ReflectRemoteToolsMessage(AZ::ReflectContext* reflection);
 
     protected:
-        AZ::u64 m_msgId;
-        AZ::u32 m_senderTargetId;
-        const void* m_customBlob;
-        AZ::u32 m_customBlobSize;
-        bool m_isBlobOwner;
-        bool m_immediateSelfDispatch;
+        AZ::u64 m_msgId = 0;
+        AZ::u32 m_senderTargetId = 0;
+        AZStd::span<AZStd::byte const> m_customBlob;
+        bool m_isBlobOwner = false;
     };
 
     using RemoteToolsMessagePointer = AZStd::intrusive_ptr<RemoteToolsMessage>;
     using RemoteToolsMessageQueue = AZStd::deque<RemoteToolsMessagePointer, AZ::OSStdAllocator>;
     
     // id for the local application
-    static constexpr AZ::u32 s_selfNetworkId = 0xFFFFFFFF;
+    static constexpr AZ::u32 SelfNetworkId = 0xFFFFFFFF;
+    // const value for an invalid connection based AzNetworking::ConnectionId
+    static constexpr AZ::u32 InvalidRemoteToolsConnectionId = 0xFFFFFFFF;
 
     class RemoteToolsEndpointInfo final
     {
@@ -124,7 +110,6 @@ namespace AzFramework
 
         explicit RemoteToolsEndpointInfo(AZStd::string displayName = AZStd::string{}, AZ::u32 networkId = 0)
             : m_displayName(AZStd::move(displayName))
-            , m_persistentId(0)
             , m_networkId(networkId)
         {
         }
@@ -163,8 +148,8 @@ namespace AzFramework
 
     private:
         AZStd::string m_displayName;
-        AZ::u32 m_persistentId; // this is a CRC key used to identify a RemoteTools target
-        AZ::u32 m_networkId; // this is the connection id, used for AzNetworking communications.
+        AZ::u32 m_persistentId = 0; // this is a CRC key used to identify a RemoteTools target
+        AZ::u32 m_networkId = 0; // this is the connection id, used for AzNetworking communications.
     };
 
     using RemoteToolsEndpointContainer = AZStd::unordered_map<AZ::u32, RemoteToolsEndpointInfo>;

Code/Framework/AzFramework/AzFramework/Network/IRemoteTools.inl

@@ -14,35 +14,30 @@ namespace AzFramework
     {
         if (m_isBlobOwner)
         {
-            azfree(const_cast<void*>(m_customBlob), AZ::OSAllocator);
+            azfree(const_cast<AZStd::byte*>(m_customBlob.data()), AZ::OSAllocator, m_customBlob.size());
         }
     }
 
     inline void RemoteToolsMessage::AddCustomBlob(const void* blob, size_t blobSize, bool ownBlob)
     {
-        m_customBlob = blob;
-        m_customBlobSize = static_cast<AZ::u32>(blobSize);
+        m_customBlob = AZStd::span<AZStd::byte const>(reinterpret_cast<const AZStd::byte*>(blob), blobSize);
         m_isBlobOwner = ownBlob;
     }
 
-    inline void RemoteToolsMessage::SetImmediateSelfDispatchEnabled(bool immediateSelfDispatchEnabled)
-    {
-        m_immediateSelfDispatch = immediateSelfDispatchEnabled;
-    }
-
-    inline bool RemoteToolsMessage::IsImmediateSelfDispatchEnabled() const
+    inline void RemoteToolsMessage::AddCustomBlob(AZStd::span<AZStd::byte const> blob, bool ownBlob)
     {
-        return m_immediateSelfDispatch;
+        m_customBlob = blob;
+        m_isBlobOwner = ownBlob;
     }
 
-    inline const void* RemoteToolsMessage::GetCustomBlob() const
+    inline const AZStd::span<AZStd::byte const> RemoteToolsMessage::GetCustomBlob() const
     {
         return m_customBlob;
     }
 
     inline size_t RemoteToolsMessage::GetCustomBlobSize() const
     {
-        return m_customBlobSize;
+        return m_customBlob.size();
     }
 
     inline bool RemoteToolsMessage::GetIsBlobOwner() const
@@ -70,20 +65,18 @@ namespace AzFramework
         AZ::SerializeContext* serializeContext = azrtti_cast<AZ::SerializeContext*>(reflection);
         if (serializeContext)
         {
-            serializeContext->Class<RemoteToolsMessage>()
-                ->Field("MsgId", &RemoteToolsMessage::m_msgId)
-                ->Field("BinaryBlobSize", &RemoteToolsMessage::m_customBlobSize);
+            serializeContext->Class<RemoteToolsMessage>()->Field("MsgId", &RemoteToolsMessage::m_msgId);
         }
     }
 
     inline bool RemoteToolsEndpointInfo::IsSelf() const
     {
-        return m_networkId == s_selfNetworkId;
+        return m_networkId == SelfNetworkId;
     }
 
     inline bool RemoteToolsEndpointInfo::IsOnline() const
     {
-        return m_networkId != 0xFFFFFFFF;
+        return m_networkId != InvalidRemoteToolsConnectionId;
     }
 
     inline bool RemoteToolsEndpointInfo::IsValid() const

Code/Framework/AzFramework/AzFramework/Script/ScriptRemoteDebugging.cpp

@@ -646,11 +646,11 @@ namespace AzFramework
                 {
                     if (sender.IsSelf() && m_debugger.IsSelf() && m_executionState == SDA_STATE_RUNNING)
                     {
-                        AZ_Assert(request->GetCustomBlob(), "ScriptDebugAgent was asked to execute a script but script is missing!");
+                        AZ_Assert(!request->GetCustomBlob().empty(), "ScriptDebugAgent was asked to execute a script but script is missing!");
                         ScriptDebugAckExecute response;
                         response.m_moduleName = request->m_context;
                         response.m_result =
-                            m_curContext->Execute(reinterpret_cast<const char*>(request->GetCustomBlob()), request->m_context.c_str());
+                            m_curContext->Execute(reinterpret_cast<const char*>(request->GetCustomBlob().data()), request->m_context.c_str());
                         RemoteToolsInterface::Get()->SendRemoteToolsMessage(sender, response);
                     }
                     else

Code/Tools/LuaIDE/Source/StandaloneToolsApplication.cpp

@@ -88,7 +88,7 @@ namespace StandaloneTools
 
     bool BaseApplication::StartDebugService()
     {
-#if !defined(_RELEASE)
+#if defined(ENABLE_REMOTE_TOOLS)
         auto* remoteToolsInterface = AzFramework::RemoteToolsInterface::Get();
         if (remoteToolsInterface)
         {

Gems/RemoteTools/Code/CMakeLists.txt

@@ -14,7 +14,7 @@
 #            <restricted_folder>/<platform_name>/Gems/RemoteTools/Code
 o3de_pal_dir(pal_dir ${CMAKE_CURRENT_LIST_DIR}/Platform/${PAL_PLATFORM_NAME} "${gem_restricted_path}" "${gem_path}" "${gem_name}")
 
-# Now that we have the platform abstraction layer (PAL) folder for this folder, thats where we will find the
+# Now that we have the platform abstraction layer (PAL) folder for this folder, that's where we will find the
 # traits for this platform. Traits for a platform are defines for things like whether or not something in this gem
 # is supported by this platform.
 include(${pal_dir}/PAL_${PAL_PLATFORM_NAME_LOWERCASE}.cmake)

Gems/RemoteTools/Code/Source/RemoteToolsEditorSystemComponent.cpp

@@ -1,61 +0,0 @@
-/*
- * Copyright (c) Contributors to the Open 3D Engine Project.
- * For complete copyright and license terms please see the LICENSE at the root of this distribution.
- *
- * SPDX-License-Identifier: Apache-2.0 OR MIT
- *
- */
-
-#include <AzCore/Serialization/SerializeContext.h>
-#include <RemoteToolsEditorSystemComponent.h>
-
-namespace RemoteTools
-{
-    void RemoteToolsEditorSystemComponent::Reflect(AZ::ReflectContext* context)
-    {
-        if (auto serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
-        {
-            serializeContext->Class<RemoteToolsEditorSystemComponent, RemoteToolsSystemComponent>()
-                ->Version(0);
-        }
-    }
-
-    RemoteToolsEditorSystemComponent::RemoteToolsEditorSystemComponent() = default;
-
-    RemoteToolsEditorSystemComponent::~RemoteToolsEditorSystemComponent() = default;
-
-    void RemoteToolsEditorSystemComponent::GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided)
-    {
-        BaseSystemComponent::GetProvidedServices(provided);
-        provided.push_back(AZ_CRC_CE("RemoteToolsEditorService"));
-    }
-
-    void RemoteToolsEditorSystemComponent::GetIncompatibleServices(AZ::ComponentDescriptor::DependencyArrayType& incompatible)
-    {
-        BaseSystemComponent::GetIncompatibleServices(incompatible);
-        incompatible.push_back(AZ_CRC_CE("RemoteToolsEditorService"));
-    }
-
-    void RemoteToolsEditorSystemComponent::GetRequiredServices([[maybe_unused]] AZ::ComponentDescriptor::DependencyArrayType& required)
-    {
-        BaseSystemComponent::GetRequiredServices(required);
-    }
-
-    void RemoteToolsEditorSystemComponent::GetDependentServices([[maybe_unused]] AZ::ComponentDescriptor::DependencyArrayType& dependent)
-    {
-        BaseSystemComponent::GetDependentServices(dependent);
-    }
-
-    void RemoteToolsEditorSystemComponent::Activate()
-    {
-        RemoteToolsSystemComponent::Activate();
-        AzToolsFramework::EditorEvents::Bus::Handler::BusConnect();
-    }
-
-    void RemoteToolsEditorSystemComponent::Deactivate()
-    {
-        AzToolsFramework::EditorEvents::Bus::Handler::BusDisconnect();
-        RemoteToolsSystemComponent::Deactivate();
-    }
-
-} // namespace RemoteTools

Gems/RemoteTools/Code/Source/RemoteToolsEditorSystemComponent.h

@@ -1,40 +0,0 @@
-/*
- * Copyright (c) Contributors to the Open 3D Engine Project.
- * For complete copyright and license terms please see the LICENSE at the root of this distribution.
- *
- * SPDX-License-Identifier: Apache-2.0 OR MIT
- *
- */
-
-#pragma once
-
-#include <RemoteToolsSystemComponent.h>
-
-#include <AzToolsFramework/Entity/EditorEntityContextBus.h>
-
-namespace RemoteTools
-{
-    /// System component for RemoteTools editor
-    class RemoteToolsEditorSystemComponent
-        : public RemoteToolsSystemComponent
-        , private AzToolsFramework::EditorEvents::Bus::Handler
-    {
-        using BaseSystemComponent = RemoteToolsSystemComponent;
-    public:
-        AZ_COMPONENT(RemoteToolsEditorSystemComponent, "{66a3f96b-677e-47fb-8c3a-17fd4c9b7bbd}", BaseSystemComponent);
-        static void Reflect(AZ::ReflectContext* context);
-
-        RemoteToolsEditorSystemComponent();
-        ~RemoteToolsEditorSystemComponent();
-
-    private:
-        static void GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided);
-        static void GetIncompatibleServices(AZ::ComponentDescriptor::DependencyArrayType& incompatible);
-        static void GetRequiredServices(AZ::ComponentDescriptor::DependencyArrayType& required);
-        static void GetDependentServices(AZ::ComponentDescriptor::DependencyArrayType& dependent);
-
-        // AZ::Component
-        void Activate() override;
-        void Deactivate() override;
-    };
-} // namespace RemoteTools

Gems/RemoteTools/Code/Source/RemoteToolsSystemComponent.cpp

@@ -105,9 +105,12 @@ namespace RemoteTools
         AZ::SystemTickBus::Handler::BusDisconnect();
         m_joinThread = nullptr;
         m_outboxThread = nullptr;
-        for (auto registryIt = m_entryRegistry.begin(); registryIt != m_entryRegistry.end(); ++registryIt)
+        if (AzNetworking::INetworking* networking = AZ::Interface<AzNetworking::INetworking>::Get())
         {
-            AZ::Interface<AzNetworking::INetworking>::Get()->DestroyNetworkInterface(registryIt->second.m_name);
+            for (auto registryIt = m_entryRegistry.begin(); registryIt != m_entryRegistry.end(); ++registryIt)
+            {
+                networking->DestroyNetworkInterface(registryIt->second.m_name);
+            }
         }
         m_entryRegistry.clear();
     }
@@ -314,7 +317,6 @@ namespace RemoteTools
         if (target.IsSelf())
         {
             AzFramework::RemoteToolsMessage* inboxMessage = aznew AzFramework::RemoteToolsMessage(msg.GetId());
-            inboxMessage->SetImmediateSelfDispatchEnabled(msg.IsImmediateSelfDispatchEnabled());
             inboxMessage->SetSenderTargetId(target.GetPersistentId());
 
             if (msg.GetCustomBlobSize() > 0)
@@ -322,12 +324,12 @@ namespace RemoteTools
                 if (msg.GetIsBlobOwner())
                 {
                     void* blob = azmalloc(msg.GetCustomBlobSize(), 16, AZ::OSAllocator);
-                    memcpy(blob, msg.GetCustomBlob(), msg.GetCustomBlobSize());
+                    memcpy(blob, msg.GetCustomBlob().data(), msg.GetCustomBlobSize());
                     inboxMessage->AddCustomBlob(blob, msg.GetCustomBlobSize(), true);
                 }
                 else
                 {
-                    inboxMessage->AddCustomBlob(msg.GetCustomBlob(), msg.GetCustomBlobSize(), false);
+                    inboxMessage->AddCustomBlob(msg.GetCustomBlob(), false);
                 }
             }
 
@@ -351,7 +353,7 @@ namespace RemoteTools
         size_t customBlobSize = msg.GetCustomBlobSize();
         if (msg.GetCustomBlobSize() > 0)
         {
-            outMsg.Write(customBlobSize, msg.GetCustomBlob());
+            outMsg.Write(customBlobSize, msg.GetCustomBlob().data());
         }
 
         AzNetworking::INetworkInterface* networkInterface =

Gems/RemoteTools/Code/Source/Utilities/RemoteToolsJoinThread.h

@@ -31,10 +31,10 @@ namespace RemoteTools
         AZ_DISABLE_COPY_MOVE(RemoteToolsJoinThread);
 
         //! Invoked on thread start
-        void OnStart() override{};
+        void OnStart() override{}
 
         //! Invoked on thread stop
-        void OnStop() override{};
+        void OnStop() override{}
 
         //! Invoked on thread update to poll for a Target host to join
         //! @param updateRateMs The amount of time the thread can spend in OnUpdate in ms

Gems/RemoteTools/Code/Source/Utilities/RemoteToolsOutboxThread.cpp

@@ -31,13 +31,12 @@ namespace RemoteTools
     void RemoteToolsOutboxThread::PushOutboxMessage(
         AzNetworking::INetworkInterface* netInterface,
         AzNetworking::ConnectionId connectionId, OutboundToolingDatum&& datum)
-    {
-        OutboundRemoteToolsMessage message;
+    { 
+        m_outboxMutex.lock();
+        auto& message = m_outbox.emplace_back();
         message.netInterface = netInterface;
         message.connectionId = connectionId;
         message.datum = datum;
-        m_outboxMutex.lock();
-        m_outbox.push_back(message);
         m_outboxMutex.unlock();
     }
 

Gems/RemoteTools/Code/Source/Utilities/RemoteToolsOutboxThread.h

@@ -57,7 +57,7 @@ namespace RemoteTools
         //! Invoked on thread stop
         void OnStop() override;
 
-        //! Invoked on thread update to poll for a Target host to join
+        //! Invoked on thread update to poll for a target host to join
         //! @param updateRateMs The amount of time the thread can spend in OnUpdate in ms
         void OnUpdate(AZ::TimeMs updateRateMs) override;
 

Gems/ScriptCanvas/Code/Include/ScriptCanvas/Debugger/ClientTransceiver.cpp

@@ -53,8 +53,7 @@ namespace ScriptCanvas
         void ClientTransceiver::AddBreakpoint(const Breakpoint& breakpoint)
         {
             SCRIPT_CANVAS_DEBUGGER_TRACE_CLIENT("TRX sending AddBreakpoint Request %s", breakpoint.ToString().data());
-            AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-            if (remoteTools)
+            if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
             {
                 remoteTools->SendRemoteToolsMessage(m_currentTarget, Message::AddBreakpointRequest(breakpoint));
             }
@@ -138,8 +137,7 @@ namespace ScriptCanvas
         void ClientTransceiver::DiscoverNetworkTargets()
         {
             AzFramework::RemoteToolsEndpointContainer targets;
-            AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-            if (remoteTools)
+            if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
             {
                 remoteTools->EnumTargetInfos(ScriptCanvas::RemoteToolsKey, targets);
             }
@@ -170,8 +168,7 @@ namespace ScriptCanvas
         AzFramework::RemoteToolsEndpointInfo ClientTransceiver::GetNetworkTarget()
         {
             AzFramework::RemoteToolsEndpointInfo targetInfo;
-            AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-            if (remoteTools)
+            if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
             {
                 targetInfo = RemoteToolsInterface::Get()->GetDesiredEndpoint(ScriptCanvas::RemoteToolsKey);
             }
@@ -446,8 +443,7 @@ namespace ScriptCanvas
 
         void ClientTransceiver::OnSystemTick()
         {
-            AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-            if (remoteTools)
+            if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
             {
                 remoteTools->SendRemoteToolsMessage(m_currentTarget, Message::AddTargetsRequest(m_addCache));
                 m_connectionState.Merge(m_addCache);
@@ -466,8 +462,7 @@ namespace ScriptCanvas
             if (!m_currentTarget.IsValid())
             {
                 m_resetDesiredTarget = true;
-                AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-                if (remoteTools)
+                if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
                 {
                     m_previousDesiredInfo = remoteTools->GetDesiredEndpoint(ScriptCanvas::RemoteToolsKey);
                     remoteTools->SetDesiredEndpointInfo(ScriptCanvas::RemoteToolsKey, m_selfTarget);
@@ -497,8 +492,7 @@ namespace ScriptCanvas
 
         void ClientTransceiver::StopLogging()
         {
-            AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get();
-            if (remoteTools)
+            if (AzFramework::IRemoteTools* remoteTools = RemoteToolsInterface::Get())
             {
                 remoteTools->SendRemoteToolsMessage(m_currentTarget, Message::StopLoggingRequest());
             }

Gems/ScriptCanvas/Code/Include/ScriptCanvas/Debugger/Messages/Notify.h

@@ -28,11 +28,7 @@ namespace ScriptCanvas
                 AZ_CLASS_ALLOCATOR(Notification, AZ::SystemAllocator, 0);
                 AZ_RTTI(Notification, "{2FBEC565-7F5F-435E-8BC6-DD17CC1FABE7}", AzFramework::RemoteToolsMessage);
 
-                Notification()
-                    : AzFramework::RemoteToolsMessage(k_serviceNotificationsMsgSlotId)
-                {
-                    SetImmediateSelfDispatchEnabled(true);
-                }
+                Notification() : AzFramework::RemoteToolsMessage(k_serviceNotificationsMsgSlotId) {}
 
                 virtual void Visit(NotificationVisitor& visitor) = 0;
             };

Gems/ScriptCanvas/Code/Include/ScriptCanvas/Debugger/Messages/Request.h

@@ -28,11 +28,7 @@ namespace ScriptCanvas
                 AZ_CLASS_ALLOCATOR(Request, AZ::SystemAllocator, 0);
                 AZ_RTTI(Request, "{0283335F-E3FF-4292-99BA-36A289DFED87}", AzFramework::RemoteToolsMessage);
 
-                Request()
-                    : AzFramework::RemoteToolsMessage(k_clientRequestsMsgSlotId)
-                {
-                    SetImmediateSelfDispatchEnabled(true);
-                }
+                Request() : AzFramework::RemoteToolsMessage(k_clientRequestsMsgSlotId) {}
 
                 virtual void Visit(RequestVisitor& visitor) = 0;
             };