diff --git a/examples/DSPDemo/Source/MainComponent.cpp b/examples/DSPDemo/Source/MainComponent.cpp
index 77968ba14b..08fc4d0d48 100644
--- a/examples/DSPDemo/Source/MainComponent.cpp
+++ b/examples/DSPDemo/Source/MainComponent.cpp
@@ -221,7 +221,7 @@ void MainContentComponent::setupDemoColours()
     if (xml != nullptr)
     {
         auto colourSchemeTree = ValueTree::fromXml (*xml);
-        auto& scheme = codeEditor.getColourScheme();
+        CodeEditorComponent::ColourScheme scheme (codeEditor.getColourScheme());
 
         for (auto& type : scheme.types)
         {
@@ -230,6 +230,8 @@ void MainContentComponent::setupDemoColours()
             if (colour.isValid())
                 type.colour = Colour::fromString (colour ["colour"].toString());
         }
+
+        codeEditor.setColourScheme (scheme);
     }
 
     codeEditor.setScrollbarThickness (6);
diff --git a/examples/Demo/Source/Demos/WavefrontObjParser.h b/examples/Demo/Source/Demos/WavefrontObjParser.h
index 02c85f67e5..6d3eb9517c 100644
--- a/examples/Demo/Source/Demos/WavefrontObjParser.h
+++ b/examples/Demo/Source/Demos/WavefrontObjParser.h
@@ -249,7 +249,7 @@ private:
     };
 
     static Shape* parseFaceGroup (const Mesh& srcMesh,
-                                  const Array<Face>& faceGroup,
+                                  Array<Face>& faceGroup,
                                   const Material& material,
                                   const String& name)
     {
diff --git a/examples/NetworkGraphicsDemo/Source/MasterComponent.h b/examples/NetworkGraphicsDemo/Source/MasterComponent.h
index d3eaea7668..c260e759cb 100644
--- a/examples/NetworkGraphicsDemo/Source/MasterComponent.h
+++ b/examples/NetworkGraphicsDemo/Source/MasterComponent.h
@@ -369,7 +369,7 @@ private:
             canvas.clients.add ({ c.name, c.centre, c.scaleFactor });
     }
 
-    Client* getClient (const String& name) const
+    const Client* getClient (const String& name) const
     {
         for (auto& c : clients)
             if (c.name == name)
@@ -378,6 +378,11 @@ private:
         return nullptr;
     }
 
+    Client* getClient (const String& name)
+    {
+        return const_cast<Client*> (static_cast<const MasterContentComponent&> (*this).getClient (name));
+    }
+
     //==============================================================================
     void oscMessageReceived (const OSCMessage& message) override
     {
diff --git a/examples/NetworkGraphicsDemo/Source/SharedCanvas.h b/examples/NetworkGraphicsDemo/Source/SharedCanvas.h
index 842d05650c..5688c7bb22 100644
--- a/examples/NetworkGraphicsDemo/Source/SharedCanvas.h
+++ b/examples/NetworkGraphicsDemo/Source/SharedCanvas.h
@@ -455,7 +455,7 @@ struct BlockPacketiser
 
         while (remaining > 0)
         {
-            const int num = jmin (maxBlockSize, remaining);
+            auto num = (int) jmin (maxBlockSize, remaining);
             blocks.add (MemoryBlock (addBytesToPointer (data.getData(), offset), (size_t) num));
             offset += num;
             remaining -= num;
diff --git a/examples/OSCMonitor/Source/OSCLogListBox.h b/examples/OSCMonitor/Source/OSCLogListBox.h
index 3cc04d83de..e29fc648ad 100644
--- a/examples/OSCMonitor/Source/OSCLogListBox.h
+++ b/examples/OSCMonitor/Source/OSCLogListBox.h
@@ -76,8 +76,8 @@ public:
 
         if (! message.isEmpty())
         {
-            for (OSCArgument* arg = message.begin(); arg != message.end(); ++arg)
-                addOSCMessageArgument (*arg, level + 1);
+            for (auto& arg : message)
+                addOSCMessageArgument (arg, level + 1);
         }
 
         triggerAsyncUpdate();
@@ -92,12 +92,12 @@ public:
                         + "- osc bundle, time tag = "
                         + timeTag.toTime().toString (true, true, true, true));
 
-        for (OSCBundle::Element* element = bundle.begin(); element != bundle.end(); ++element)
+        for (auto& element : bundle)
         {
-            if (element->isMessage())
-                addOSCMessage (element->getMessage(), level + 1);
-            else if (element->isBundle())
-                addOSCBundle (element->getBundle(), level + 1);
+            if (element.isMessage())
+                addOSCMessage (element.getMessage(), level + 1);
+            else if (element.isBundle())
+                addOSCBundle (element.getBundle(), level + 1);
         }
 
         triggerAsyncUpdate();
diff --git a/examples/OpenGLAppExample/Source/Resources/WavefrontObjParser.h b/examples/OpenGLAppExample/Source/Resources/WavefrontObjParser.h
index 02c85f67e5..6d3eb9517c 100644
--- a/examples/OpenGLAppExample/Source/Resources/WavefrontObjParser.h
+++ b/examples/OpenGLAppExample/Source/Resources/WavefrontObjParser.h
@@ -249,7 +249,7 @@ private:
     };
 
     static Shape* parseFaceGroup (const Mesh& srcMesh,
-                                  const Array<Face>& faceGroup,
+                                  Array<Face>& faceGroup,
                                   const Material& material,
                                   const String& name)
     {
diff --git a/extras/Projucer/Source/CodeEditor/jucer_LiveBuildCodeEditor.h b/extras/Projucer/Source/CodeEditor/jucer_LiveBuildCodeEditor.h
index 1cae43f414..9ed2c8e843 100644
--- a/extras/Projucer/Source/CodeEditor/jucer_LiveBuildCodeEditor.h
+++ b/extras/Projucer/Source/CodeEditor/jucer_LiveBuildCodeEditor.h
@@ -234,7 +234,7 @@ private:
             Array<ClassDatabase::Class*> newClasses;
 
             if (childProcess != nullptr)
-                childProcess->getComponentList().globalNamespace.findClassesDeclaredInFile (newClasses, file);
+                const_cast <ClassDatabase::ClassList&> (childProcess->getComponentList()).globalNamespace.findClassesDeclaredInFile (newClasses, file);
 
             for (int i = newClasses.size(); --i >= 0;)
                 if (! newClasses.getUnchecked(i)->getInstantiationFlags().canBeInstantiated())
diff --git a/extras/Projucer/Source/LiveBuildEngine/jucer_ClassDatabase.h b/extras/Projucer/Source/LiveBuildEngine/jucer_ClassDatabase.h
index 579e380eae..aefbbc6fc9 100644
--- a/extras/Projucer/Source/LiveBuildEngine/jucer_ClassDatabase.h
+++ b/extras/Projucer/Source/LiveBuildEngine/jucer_ClassDatabase.h
@@ -291,15 +291,20 @@ struct ClassDatabase
             return classDeclaration;
         }
 
-        MemberInfo* findMember (const String& memberName) const
+        const MemberInfo* findMember (const String& memberName) const
         {
-            for (MemberInfo& m : members)
+            for (auto& m : members)
                 if (m.getName() == memberName)
                     return &m;
 
             return nullptr;
         }
 
+        MemberInfo* findMember (const String& memberName)
+        {
+            return const_cast<MemberInfo*> (static_cast<const Class&>(*this).findMember (memberName));
+        }
+
         const MethodInfo* getDefaultConstructor() const
         {
             for (const MethodInfo& m : methods)
@@ -340,15 +345,15 @@ struct ClassDatabase
                 if (m->definition.isValid())
                     return m->definition.file;
 
-            for (MethodInfo& m : methods)
+            for (auto& m : methods)
                 if (m.definition.isValid() && File (m.definition.file).hasFileExtension ("cpp;mm"))
                     return m.definition.file;
 
-            for (MethodInfo& m : methods)
+            for (auto& m : methods)
                 if ((m.flags & MethodInfo::isConstructor) != 0 && m.definition.isValid())
                     return m.definition.file;
 
-            for (MethodInfo& m : methods)
+            for (auto& m : methods)
                 if (m.definition.isValid() && File (m.definition.file).exists())
                     return m.definition.file;
 
@@ -380,9 +385,9 @@ struct ClassDatabase
             if (other.classDeclaration.isValid())
                 classDeclaration = other.classDeclaration;
 
-            for (const MemberInfo& m : other.members)
+            for (auto& m : other.members)
             {
-                if (MemberInfo* existing = findMember (m.getName()))
+                if (auto* existing = findMember (m.getName()))
                     existing->mergeWith (m);
                 else
                     members.add (m);
@@ -496,14 +501,14 @@ struct ClassDatabase
             return false;
         }
 
-        Class* findClass (const String& className) const
+        const Class* findClass (const String& className) const
         {
-            for (Class& c : components)
+            for (auto& c : components)
                 if (c.getName() == className)
                     return &c;
 
-            for (const auto& n : namespaces)
-                if (Class* c = n.findClass (className))
+            for (auto& n : namespaces)
+                if (auto* c = n.findClass (className))
                     return c;
 
             return nullptr;
@@ -511,19 +516,19 @@ struct ClassDatabase
 
         const MemberInfo* findClassMemberInfo (const String& className, const String& memberName) const
         {
-            if (const Class* classInfo = findClass (className))
+            if (auto* classInfo = findClass (className))
                 return classInfo->findMember (memberName);
 
             return nullptr;
         }
 
-        void findClassesDeclaredInFile (Array<Class*>& results, const File& file) const
+        void findClassesDeclaredInFile (Array<Class*>& results, const File& file)
         {
-            for (Class& c : components)
+            for (auto& c : components)
                 if (c.isDeclaredInFile (file))
                     results.add (&c);
 
-            for (const auto& n : namespaces)
+            for (auto& n : namespaces)
                 n.findClassesDeclaredInFile (results, file);
         }
 
@@ -553,7 +558,7 @@ struct ClassDatabase
                 components.getReference (existing).mergeWith (c);
         }
 
-        Namespace* findNamespace (const String& targetName) const
+        Namespace* findNamespace (const String& targetName)
         {
             for (auto& n : namespaces)
                 if (n.name == targetName)
@@ -593,13 +598,13 @@ struct ClassDatabase
             namespaces.swapWith (other.namespaces);
         }
 
-        void nudgeAllCodeRanges (const String& file, int index, int delta) const
+        void nudgeAllCodeRanges (const String& file, int index, int delta)
         {
             for (auto& c : components)  c.nudgeAllCodeRanges (file, index, delta);
             for (auto& n : namespaces)  n.nudgeAllCodeRanges (file, index, delta);
         }
 
-        void fileContentChanged (const String& file) const
+        void fileContentChanged (const String& file)
         {
             for (auto& c : components)  c.fileContentChanged (file);
             for (auto& n : namespaces)  n.fileContentChanged (file);
diff --git a/extras/Projucer/Source/LiveBuildEngine/jucer_ErrorList.h b/extras/Projucer/Source/LiveBuildEngine/jucer_ErrorList.h
index 637d019de5..60cfe34ecf 100644
--- a/extras/Projucer/Source/LiveBuildEngine/jucer_ErrorList.h
+++ b/extras/Projucer/Source/LiveBuildEngine/jucer_ErrorList.h
@@ -42,7 +42,7 @@ struct ErrorList    : public ChangeBroadcaster
         }
         else
         {
-            for (DiagnosticMessage& d : messages)
+            for (auto& d : messages)
                 if (d.isError())
                     dest.add (d);
         }
diff --git a/extras/Projucer/Source/Settings/jucer_AppearanceSettings.cpp b/extras/Projucer/Source/Settings/jucer_AppearanceSettings.cpp
index f9a24dddbc..6087bbbc1f 100644
--- a/extras/Projucer/Source/Settings/jucer_AppearanceSettings.cpp
+++ b/extras/Projucer/Source/Settings/jucer_AppearanceSettings.cpp
@@ -40,11 +40,11 @@ AppearanceSettings::AppearanceSettings (bool updateAppWhenChanged)
         CPlusPlusCodeTokeniser tokeniser;
         CodeEditorComponent editor (doc, &tokeniser);
 
-        const CodeEditorComponent::ColourScheme cs (editor.getColourScheme());
+        CodeEditorComponent::ColourScheme cs (editor.getColourScheme());
 
         for (int i = cs.types.size(); --i >= 0;)
         {
-            CodeEditorComponent::ColourScheme::TokenType& t = cs.types.getReference(i);
+            auto& t = cs.types.getReference(i);
             getColourValue (t.name) = t.colour.toString();
         }
 
diff --git a/modules/juce_audio_basics/midi/juce_MidiMessageSequence.cpp b/modules/juce_audio_basics/midi/juce_MidiMessageSequence.cpp
index 4b94437247..a0effbef68 100644
--- a/modules/juce_audio_basics/midi/juce_MidiMessageSequence.cpp
+++ b/modules/juce_audio_basics/midi/juce_MidiMessageSequence.cpp
@@ -80,8 +80,10 @@ MidiMessageSequence::MidiEventHolder* MidiMessageSequence::getEventPointer (int
     return list[index];
 }
 
-MidiMessageSequence::MidiEventHolder** MidiMessageSequence::begin() const noexcept     { return list.begin(); }
-MidiMessageSequence::MidiEventHolder** MidiMessageSequence::end() const noexcept       { return list.end(); }
+MidiMessageSequence::MidiEventHolder** MidiMessageSequence::begin() noexcept                { return list.begin(); }
+MidiMessageSequence::MidiEventHolder*const* MidiMessageSequence::begin() const noexcept     { return list.begin(); }
+MidiMessageSequence::MidiEventHolder** MidiMessageSequence::end() noexcept                  { return list.end(); }
+MidiMessageSequence::MidiEventHolder*const* MidiMessageSequence::end() const noexcept       { return list.end(); }
 
 double MidiMessageSequence::getTimeOfMatchingKeyUp (int index) const noexcept
 {
diff --git a/modules/juce_audio_basics/midi/juce_MidiMessageSequence.h b/modules/juce_audio_basics/midi/juce_MidiMessageSequence.h
index 8f5e3f6994..05025a89e8 100644
--- a/modules/juce_audio_basics/midi/juce_MidiMessageSequence.h
+++ b/modules/juce_audio_basics/midi/juce_MidiMessageSequence.h
@@ -101,10 +101,12 @@ public:
     MidiEventHolder* getEventPointer (int index) const noexcept;
 
     /** Iterator for the list of MidiEventHolders */
-    MidiEventHolder** begin() const noexcept;
+    MidiEventHolder** begin() noexcept;
+    MidiEventHolder*const* begin() const noexcept;
 
     /** Iterator for the list of MidiEventHolders */
-    MidiEventHolder** end() const noexcept;
+    MidiEventHolder** end() noexcept;
+    MidiEventHolder*const* end() const noexcept;
 
     /** Returns the time of the note-up that matches the note-on at this index.
         If the event at this index isn't a note-on, it'll just return 0.
diff --git a/modules/juce_audio_basics/mpe/juce_MPEInstrument.cpp b/modules/juce_audio_basics/mpe/juce_MPEInstrument.cpp
index 3908af7c54..539b241979 100644
--- a/modules/juce_audio_basics/mpe/juce_MPEInstrument.cpp
+++ b/modules/juce_audio_basics/mpe/juce_MPEInstrument.cpp
@@ -231,7 +231,7 @@ void MPEInstrument::processMidiAllNotesOffMessage (const MidiMessage& message)
             }
         }
     }
-    else if (MPEZone* zone = zoneLayout.getZoneByMasterChannel (message.getChannel()))
+    else if (auto* zone = zoneLayout.getZoneByMasterChannel (message.getChannel()))
     {
         for (int i = notes.size(); --i >= 0;)
         {
@@ -400,7 +400,7 @@ void MPEInstrument::updateDimension (int midiChannel, MPEDimension& dimension, M
 }
 
 //==============================================================================
-void MPEInstrument::updateDimensionMaster (MPEZone& zone, MPEDimension& dimension, MPEValue value)
+void MPEInstrument::updateDimensionMaster (const MPEZone& zone, MPEDimension& dimension, MPEValue value)
 {
     auto channels = zone.getNoteChannelRange();
 
@@ -441,7 +441,7 @@ void MPEInstrument::updateDimensionForNote (MPENote& note, MPEDimension& dimensi
 }
 
 //==============================================================================
-void MPEInstrument::callListenersDimensionChanged (MPENote& note, MPEDimension& dimension)
+void MPEInstrument::callListenersDimensionChanged (const MPENote& note, const MPEDimension& dimension)
 {
     if (&dimension == &pressureDimension)  { listeners.call ([&] (Listener& l) { l.notePressureChanged  (note); }); return; }
     if (&dimension == &timbreDimension)    { listeners.call ([&] (Listener& l) { l.noteTimbreChanged    (note); }); return; }
@@ -555,7 +555,7 @@ int MPEInstrument::getNumPlayingNotes() const noexcept
 
 MPENote MPEInstrument::getNote (int midiChannel, int midiNoteNumber) const noexcept
 {
-    if (MPENote* note = getNotePtr (midiChannel, midiNoteNumber))
+    if (auto* note = getNotePtr (midiChannel, midiNoteNumber))
         return *note;
 
     return MPENote();
@@ -569,7 +569,7 @@ MPENote MPEInstrument::getNote (int index) const noexcept
 //==============================================================================
 MPENote MPEInstrument::getMostRecentNote (int midiChannel) const noexcept
 {
-    if (MPENote* note = getLastNotePlayedPtr (midiChannel))
+    if (auto* note = getLastNotePlayedPtr (midiChannel))
         return *note;
 
     return MPENote();
@@ -579,7 +579,7 @@ MPENote MPEInstrument::getMostRecentNoteOtherThan (MPENote otherThanThisNote) co
 {
     for (int i = notes.size(); --i >= 0;)
     {
-        const MPENote& note = notes.getReference (i);
+        auto& note = notes.getReference (i);
 
         if (note != otherThanThisNote)
             return note;
@@ -589,11 +589,11 @@ MPENote MPEInstrument::getMostRecentNoteOtherThan (MPENote otherThanThisNote) co
 }
 
 //==============================================================================
-MPENote* MPEInstrument::getNotePtr (int midiChannel, int midiNoteNumber) const noexcept
+const MPENote* MPEInstrument::getNotePtr (int midiChannel, int midiNoteNumber) const noexcept
 {
     for (int i = 0; i < notes.size(); ++i)
     {
-        MPENote& note = notes.getReference (i);
+        auto& note = notes.getReference (i);
 
         if (note.midiChannel == midiChannel && note.initialNote == midiNoteNumber)
             return &note;
@@ -602,8 +602,13 @@ MPENote* MPEInstrument::getNotePtr (int midiChannel, int midiNoteNumber) const n
     return nullptr;
 }
 
+MPENote* MPEInstrument::getNotePtr (int midiChannel, int midiNoteNumber) noexcept
+{
+    return const_cast<MPENote*> (static_cast<const MPEInstrument&> (*this).getNotePtr (midiChannel, midiNoteNumber));
+}
+
 //==============================================================================
-MPENote* MPEInstrument::getNotePtr (int midiChannel, TrackingMode mode) const noexcept
+const MPENote* MPEInstrument::getNotePtr (int midiChannel, TrackingMode mode) const noexcept
 {
     // for the "all notes" tracking mode, this method can never possibly
     // work because it returns 0 or 1 note but there might be more than one!
@@ -616,12 +621,17 @@ MPENote* MPEInstrument::getNotePtr (int midiChannel, TrackingMode mode) const no
     return nullptr;
 }
 
+MPENote* MPEInstrument::getNotePtr (int midiChannel, TrackingMode mode) noexcept
+{
+    return const_cast<MPENote*> (static_cast<const MPEInstrument&> (*this).getNotePtr (midiChannel, mode));
+}
+
 //==============================================================================
-MPENote* MPEInstrument::getLastNotePlayedPtr (int midiChannel) const noexcept
+const MPENote* MPEInstrument::getLastNotePlayedPtr (int midiChannel) const noexcept
 {
     for (int i = notes.size(); --i >= 0;)
     {
-        MPENote& note = notes.getReference (i);
+        auto& note = notes.getReference (i);
 
         if (note.midiChannel == midiChannel
              && (note.keyState == MPENote::keyDown || note.keyState == MPENote::keyDownAndSustained))
@@ -631,15 +641,20 @@ MPENote* MPEInstrument::getLastNotePlayedPtr (int midiChannel) const noexcept
     return nullptr;
 }
 
+MPENote* MPEInstrument::getLastNotePlayedPtr (int midiChannel) noexcept
+{
+    return const_cast<MPENote*> (static_cast<const MPEInstrument&> (*this).getLastNotePlayedPtr (midiChannel));
+}
+
 //==============================================================================
-MPENote* MPEInstrument::getHighestNotePtr (int midiChannel) const noexcept
+const MPENote* MPEInstrument::getHighestNotePtr (int midiChannel) const noexcept
 {
     int initialNoteMax = -1;
-    MPENote* result = nullptr;
+    const MPENote* result = nullptr;
 
     for (int i = notes.size(); --i >= 0;)
     {
-        MPENote& note = notes.getReference (i);
+        const auto& note = notes.getReference (i);
 
         if (note.midiChannel == midiChannel
              && (note.keyState == MPENote::keyDown || note.keyState == MPENote::keyDownAndSustained)
@@ -653,14 +668,19 @@ MPENote* MPEInstrument::getHighestNotePtr (int midiChannel) const noexcept
     return result;
 }
 
-MPENote* MPEInstrument::getLowestNotePtr (int midiChannel) const noexcept
+MPENote* MPEInstrument::getHighestNotePtr (int midiChannel) noexcept
+{
+    return const_cast<MPENote*> (static_cast<const MPEInstrument&> (*this).getHighestNotePtr (midiChannel));
+}
+
+const MPENote* MPEInstrument::getLowestNotePtr (int midiChannel) const noexcept
 {
     int initialNoteMin = 128;
-    MPENote* result = nullptr;
+    const MPENote* result = nullptr;
 
     for (int i = notes.size(); --i >= 0;)
     {
-        MPENote& note = notes.getReference (i);
+        auto& note = notes.getReference (i);
 
         if (note.midiChannel == midiChannel
              && (note.keyState == MPENote::keyDown || note.keyState == MPENote::keyDownAndSustained)
@@ -674,6 +694,11 @@ MPENote* MPEInstrument::getLowestNotePtr (int midiChannel) const noexcept
     return result;
 }
 
+MPENote* MPEInstrument::getLowestNotePtr (int midiChannel) noexcept
+{
+    return const_cast<MPENote*> (static_cast<const MPEInstrument&> (*this).getLowestNotePtr (midiChannel));
+}
+
 //==============================================================================
 void MPEInstrument::releaseAllNotes()
 {
diff --git a/modules/juce_audio_basics/mpe/juce_MPEInstrument.h b/modules/juce_audio_basics/mpe/juce_MPEInstrument.h
index 82b62de4db..1605c5a839 100644
--- a/modules/juce_audio_basics/mpe/juce_MPEInstrument.h
+++ b/modules/juce_audio_basics/mpe/juce_MPEInstrument.h
@@ -351,9 +351,9 @@ private:
     MPEDimension pitchbendDimension, pressureDimension, timbreDimension;
 
     void updateDimension (int midiChannel, MPEDimension&, MPEValue);
-    void updateDimensionMaster (MPEZone&, MPEDimension&, MPEValue);
+    void updateDimensionMaster (const MPEZone&, MPEDimension&, MPEValue);
     void updateDimensionForNote (MPENote&, MPEDimension&, MPEValue);
-    void callListenersDimensionChanged (MPENote&, MPEDimension&);
+    void callListenersDimensionChanged (const MPENote&, const MPEDimension&);
     MPEValue getInitialValueForNewNote (int midiChannel, MPEDimension&) const;
 
     void processMidiNoteOnMessage (const MidiMessage&);
@@ -368,11 +368,16 @@ private:
     void handleTimbreLSB (int midiChannel, int value) noexcept;
     void handleSustainOrSostenuto (int midiChannel, bool isDown, bool isSostenuto);
 
-    MPENote* getNotePtr (int midiChannel, int midiNoteNumber) const noexcept;
-    MPENote* getNotePtr (int midiChannel, TrackingMode) const noexcept;
-    MPENote* getLastNotePlayedPtr (int midiChannel) const noexcept;
-    MPENote* getHighestNotePtr (int midiChannel) const noexcept;
-    MPENote* getLowestNotePtr (int midiChannel) const noexcept;
+    const MPENote* getNotePtr (int midiChannel, int midiNoteNumber) const noexcept;
+    MPENote* getNotePtr (int midiChannel, int midiNoteNumber) noexcept;
+    const MPENote* getNotePtr (int midiChannel, TrackingMode) const noexcept;
+    MPENote* getNotePtr (int midiChannel, TrackingMode) noexcept;
+    const MPENote* getLastNotePlayedPtr (int midiChannel) const noexcept;
+    MPENote* getLastNotePlayedPtr (int midiChannel) noexcept;
+    const MPENote* getHighestNotePtr (int midiChannel) const noexcept;
+    MPENote* getHighestNotePtr (int midiChannel) noexcept;
+    const MPENote* getLowestNotePtr (int midiChannel) const noexcept;
+    MPENote* getLowestNotePtr (int midiChannel) noexcept;
     void updateNoteTotalPitchbend (MPENote&);
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MPEInstrument)
diff --git a/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.cpp b/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.cpp
index c8f670a4a4..54d3d6a6b0 100644
--- a/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.cpp
+++ b/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.cpp
@@ -74,7 +74,7 @@ int MPEZoneLayout::getNumZones() const noexcept
     return zones.size();
 }
 
-MPEZone* MPEZoneLayout::getZoneByIndex (int index) const noexcept
+const MPEZone* MPEZoneLayout::getZoneByIndex (int index) const noexcept
 {
     if (zones.size() < index)
         return nullptr;
@@ -82,6 +82,11 @@ MPEZone* MPEZoneLayout::getZoneByIndex (int index) const noexcept
     return &(zones.getReference (index));
 }
 
+MPEZone* MPEZoneLayout::getZoneByIndex (int index) noexcept
+{
+    return const_cast<MPEZone*> (static_cast<const MPEZoneLayout&> (*this).getZoneByIndex (index));
+}
+
 void MPEZoneLayout::clearAllZones()
 {
     zones.clear();
@@ -157,42 +162,62 @@ void MPEZoneLayout::processNextMidiBuffer (const MidiBuffer& buffer)
 }
 
 //==============================================================================
-MPEZone* MPEZoneLayout::getZoneByChannel (int channel) const noexcept
+const MPEZone* MPEZoneLayout::getZoneByChannel (int channel) const noexcept
 {
-    for (auto* zone = zones.begin(); zone != zones.end(); ++zone)
-        if (zone->isUsingChannel (channel))
-            return zone;
+    for (auto& zone : zones)
+        if (zone.isUsingChannel (channel))
+            return &zone;
 
     return nullptr;
 }
 
-MPEZone* MPEZoneLayout::getZoneByMasterChannel (int channel) const noexcept
+MPEZone* MPEZoneLayout::getZoneByChannel (int channel) noexcept
 {
-    for (auto* zone = zones.begin(); zone != zones.end(); ++zone)
-        if (zone->getMasterChannel() == channel)
-            return zone;
+    return const_cast<MPEZone*> (static_cast<const MPEZoneLayout&> (*this).getZoneByChannel (channel));
+}
+
+const MPEZone* MPEZoneLayout::getZoneByMasterChannel (int channel) const noexcept
+{
+    for (auto& zone : zones)
+        if (zone.getMasterChannel() == channel)
+            return &zone;
 
     return nullptr;
 }
 
-MPEZone* MPEZoneLayout::getZoneByFirstNoteChannel (int channel) const noexcept
+MPEZone* MPEZoneLayout::getZoneByMasterChannel (int channel) noexcept
 {
-    for (auto* zone = zones.begin(); zone != zones.end(); ++zone)
-        if (zone->getFirstNoteChannel() == channel)
-            return zone;
+    return const_cast<MPEZone*> (static_cast<const MPEZoneLayout&> (*this).getZoneByMasterChannel (channel));
+}
+
+const MPEZone* MPEZoneLayout::getZoneByFirstNoteChannel (int channel) const noexcept
+{
+    for (auto& zone : zones)
+        if (zone.getFirstNoteChannel() == channel)
+            return &zone;
 
     return nullptr;
 }
 
-MPEZone* MPEZoneLayout::getZoneByNoteChannel (int channel) const noexcept
+MPEZone* MPEZoneLayout::getZoneByFirstNoteChannel (int channel) noexcept
 {
-    for (auto* zone = zones.begin(); zone != zones.end(); ++zone)
-        if (zone->isUsingChannelAsNoteChannel (channel))
-            return zone;
+    return const_cast<MPEZone*> (static_cast<const MPEZoneLayout&> (*this).getZoneByFirstNoteChannel (channel));
+}
+
+const MPEZone* MPEZoneLayout::getZoneByNoteChannel (int channel) const noexcept
+{
+    for (auto& zone : zones)
+        if (zone.isUsingChannelAsNoteChannel (channel))
+            return &zone;
 
     return nullptr;
 }
 
+MPEZone* MPEZoneLayout::getZoneByNoteChannel (int channel) noexcept
+{
+    return const_cast<MPEZone*> (static_cast<const MPEZoneLayout&> (*this).getZoneByNoteChannel (channel));
+}
+
 //==============================================================================
 void MPEZoneLayout::addListener (Listener* const listenerToAdd) noexcept
 {
diff --git a/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.h b/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.h
index c24accedd8..bbb24a6dba 100644
--- a/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.h
+++ b/modules/juce_audio_basics/mpe/juce_MPEZoneLayout.h
@@ -101,27 +101,32 @@ public:
         is no such zone. Zones are sorted by insertion order (most recently added
         zone last).
     */
-    MPEZone* getZoneByIndex (int index) const noexcept;
+    MPEZone* getZoneByIndex (int index) noexcept;
+    const MPEZone* getZoneByIndex (int index) const noexcept;
 
     /** Returns a pointer to the zone which uses the specified channel (1-16),
         or nullptr if there is no such zone.
     */
-    MPEZone* getZoneByChannel (int midiChannel) const noexcept;
+    MPEZone* getZoneByChannel (int midiChannel) noexcept;
+    const MPEZone* getZoneByChannel (int midiChannel) const noexcept;
 
     /** Returns a pointer to the zone which has the specified channel (1-16)
         as its master channel, or nullptr if there is no such zone.
     */
-    MPEZone* getZoneByMasterChannel (int midiChannel) const noexcept;
+    MPEZone* getZoneByMasterChannel (int midiChannel) noexcept;
+    const MPEZone* getZoneByMasterChannel (int midiChannel) const noexcept;
 
     /** Returns a pointer to the zone which has the specified channel (1-16)
         as its first note channel, or nullptr if there is no such zone.
     */
-    MPEZone* getZoneByFirstNoteChannel (int midiChannel) const noexcept;
+    MPEZone* getZoneByFirstNoteChannel (int midiChannel) noexcept;
+    const MPEZone* getZoneByFirstNoteChannel (int midiChannel) const noexcept;
 
     /** Returns a pointer to the zone which has the specified channel (1-16)
         as one of its note channels, or nullptr if there is no such zone.
     */
-    MPEZone* getZoneByNoteChannel (int midiChannel) const noexcept;
+    MPEZone* getZoneByNoteChannel (int midiChannel) noexcept;
+    const MPEZone* getZoneByNoteChannel (int midiChannel) const noexcept;
 
     //==============================================================================
     /** Listener class. Derive from this class to allow your class to be
diff --git a/modules/juce_audio_formats/format/juce_AudioFormatManager.h b/modules/juce_audio_formats/format/juce_AudioFormatManager.h
index 15a97a1e3f..9abed6bd59 100644
--- a/modules/juce_audio_formats/format/juce_AudioFormatManager.h
+++ b/modules/juce_audio_formats/format/juce_AudioFormatManager.h
@@ -78,10 +78,12 @@ public:
     AudioFormat* getKnownFormat (int index) const;
 
     /** Iterator access to the list of known formats. */
-    AudioFormat** begin() const noexcept            { return knownFormats.begin(); }
+    AudioFormat** begin() noexcept                       { return knownFormats.begin(); }
+    AudioFormat*const* begin() const noexcept            { return knownFormats.begin(); }
 
     /** Iterator access to the list of known formats. */
-    AudioFormat** end() const noexcept              { return knownFormats.end(); }
+    AudioFormat** end() noexcept                         { return knownFormats.end(); }
+    AudioFormat*const* end() const noexcept              { return knownFormats.end(); }
 
     /** Looks for which of the known formats is listed as being for a given file
         extension.
diff --git a/modules/juce_audio_processors/scanning/juce_KnownPluginList.h b/modules/juce_audio_processors/scanning/juce_KnownPluginList.h
index 3bfa606b5f..0b938ad507 100644
--- a/modules/juce_audio_processors/scanning/juce_KnownPluginList.h
+++ b/modules/juce_audio_processors/scanning/juce_KnownPluginList.h
@@ -61,9 +61,12 @@ public:
     PluginDescription* getType (int index) const noexcept           { return types [index]; }
 
     /** Type iteration. */
-    PluginDescription** begin() const noexcept                      { return types.begin(); }
+    PluginDescription** begin() noexcept                            { return types.begin(); }
+    PluginDescription*const* begin() const noexcept                 { return types.begin(); }
+
     /** Type iteration. */
-    PluginDescription** end() const noexcept                        { return types.end(); }
+    PluginDescription** end() noexcept                              { return types.end(); }
+    PluginDescription*const* end() const noexcept                   { return types.end(); }
 
     /** Looks for a type in the list which comes from this file. */
     PluginDescription* getTypeForFile (const String& fileOrIdentifier) const;
diff --git a/modules/juce_blocks_basics/blocks/juce_TouchList.h b/modules/juce_blocks_basics/blocks/juce_TouchList.h
index 81a4a4680d..d532492d88 100644
--- a/modules/juce_blocks_basics/blocks/juce_TouchList.h
+++ b/modules/juce_blocks_basics/blocks/juce_TouchList.h
@@ -106,7 +106,7 @@ public:
     /** If a touch is in the list, returns a pointer to the TouchEntry.
         Otherwise, returns nullptr.
     */
-    TouchEntry* find (const TouchSurface::Touch& touch) const noexcept
+    const TouchEntry* find (const TouchSurface::Touch& touch) const noexcept
     {
         for (auto& t : touches)
             if (matches (t.touch, touch))
@@ -115,17 +115,24 @@ public:
         return nullptr;
     }
 
-    /** Allows iterator access to the list of touch entries. */
-    TouchEntry* begin() const noexcept      { return touches.begin(); }
+    TouchEntry* find (const TouchSurface::Touch& touch) noexcept
+    {
+        return const_cast<TouchEntry*> (static_cast<const TouchList&> (*this).find (touch));
+    }
 
     /** Allows iterator access to the list of touch entries. */
-    TouchEntry* end() const noexcept        { return touches.end(); }
+    TouchEntry* begin() noexcept               { return touches.begin(); }
+    const TouchEntry* begin() const noexcept   { return touches.begin(); }
+
+    /** Allows iterator access to the list of touch entries. */
+    TouchEntry* end() noexcept                 { return touches.end(); }
+    const TouchEntry* end() const noexcept     { return touches.end(); }
 
     /** Retrieve a reference to particular item in the list of touch entires. */
-    TouchEntry& operator[] (const int index) { return touches.getReference (index); }
+    TouchEntry& operator[] (const int index)   { return touches.getReference (index); }
 
     /** Resets all contents, doest not generate any call-backs. */
-    void clear() noexcept                   { touches.clear(); }
+    void clear() noexcept                      { touches.clear(); }
 
 private:
     //==========================================================================
diff --git a/modules/juce_blocks_basics/littlefoot/juce_LittleFootCompiler.h b/modules/juce_blocks_basics/littlefoot/juce_LittleFootCompiler.h
index 0ac0ac8dcc..3fdf85a243 100644
--- a/modules/juce_blocks_basics/littlefoot/juce_LittleFootCompiler.h
+++ b/modules/juce_blocks_basics/littlefoot/juce_LittleFootCompiler.h
@@ -405,7 +405,7 @@ private:
                 f->block->simplify (*this);
         }
 
-        Function* findFunction (FunctionID functionID) const noexcept
+        const Function* findFunction (FunctionID functionID) const noexcept
         {
             for (auto f : functions)
                 if (f->functionID == functionID)
@@ -414,7 +414,7 @@ private:
             return nullptr;
         }
 
-        NativeFunction* findNativeFunction (FunctionID functionID) const noexcept
+        const NativeFunction* findNativeFunction (FunctionID functionID) const noexcept
         {
             for (auto& f : nativeFunctions)
                 if (f.functionID == functionID)
diff --git a/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp b/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
index e27d786c0e..27416d5e4a 100644
--- a/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
+++ b/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
@@ -443,7 +443,7 @@ struct PhysicalTopologySource::Internal
             return -1;
         }
 
-        DeviceInfo* getDeviceInfoFromUID (Block::UID uid) const noexcept
+        const DeviceInfo* getDeviceInfoFromUID (Block::UID uid) const noexcept
         {
             for (auto& d : currentDeviceInfo)
                 if (d.uid == uid)
diff --git a/modules/juce_graphics/fonts/juce_GlyphArrangement.cpp b/modules/juce_graphics/fonts/juce_GlyphArrangement.cpp
index 123e576be8..fe97d7a156 100644
--- a/modules/juce_graphics/fonts/juce_GlyphArrangement.cpp
+++ b/modules/juce_graphics/fonts/juce_GlyphArrangement.cpp
@@ -148,7 +148,7 @@ void GlyphArrangement::clear()
     glyphs.clear();
 }
 
-PositionedGlyph& GlyphArrangement::getGlyph (int index) const noexcept
+PositionedGlyph& GlyphArrangement::getGlyph (int index) noexcept
 {
     return glyphs.getReference (index);
 }
diff --git a/modules/juce_graphics/fonts/juce_GlyphArrangement.h b/modules/juce_graphics/fonts/juce_GlyphArrangement.h
index 4d617895fc..d2f854c36b 100644
--- a/modules/juce_graphics/fonts/juce_GlyphArrangement.h
+++ b/modules/juce_graphics/fonts/juce_GlyphArrangement.h
@@ -146,7 +146,7 @@ public:
                         careful not to pass an out-of-range index here, as it
                         doesn't do any bounds-checking.
     */
-    PositionedGlyph& getGlyph (int index) const noexcept;
+    PositionedGlyph& getGlyph (int index) noexcept;
 
     const PositionedGlyph* begin() const                        { return glyphs.begin(); }
     const PositionedGlyph* end() const                          { return glyphs.end(); }
diff --git a/modules/juce_gui_basics/components/juce_Desktop.cpp b/modules/juce_gui_basics/components/juce_Desktop.cpp
index 27fdd37763..ae89ed4be3 100644
--- a/modules/juce_gui_basics/components/juce_Desktop.cpp
+++ b/modules/juce_gui_basics/components/juce_Desktop.cpp
@@ -179,13 +179,13 @@ int Desktop::getMouseWheelMoveCounter() const noexcept      { return mouseWheelC
 void Desktop::incrementMouseClickCounter() noexcept         { ++mouseClickCounter; }
 void Desktop::incrementMouseWheelCounter() noexcept         { ++mouseWheelCounter; }
 
-const Array<MouseInputSource>& Desktop::getMouseSources() const noexcept        { return mouseSources->sourceArray; }
-int Desktop::getNumMouseSources() const noexcept                                { return mouseSources->sources.size(); }
-int Desktop::getNumDraggingMouseSources() const noexcept                        { return mouseSources->getNumDraggingMouseSources(); }
-MouseInputSource* Desktop::getMouseSource (int index) const noexcept            { return mouseSources->getMouseSource (index); }
-MouseInputSource* Desktop::getDraggingMouseSource (int index) const noexcept    { return mouseSources->getDraggingMouseSource (index); }
-MouseInputSource Desktop::getMainMouseSource() const noexcept                   { return MouseInputSource (mouseSources->sources.getUnchecked(0)); }
-void Desktop::beginDragAutoRepeat (int interval)                                { mouseSources->beginDragAutoRepeat (interval); }
+const Array<MouseInputSource>& Desktop::getMouseSources() const noexcept              { return mouseSources->sourceArray; }
+int Desktop::getNumMouseSources() const noexcept                                      { return mouseSources->sources.size(); }
+int Desktop::getNumDraggingMouseSources() const noexcept                              { return mouseSources->getNumDraggingMouseSources(); }
+MouseInputSource* Desktop::getMouseSource (int index) const noexcept                  { return mouseSources->getMouseSource (index); }
+MouseInputSource* Desktop::getDraggingMouseSource (int index) const noexcept          { return mouseSources->getDraggingMouseSource (index); }
+MouseInputSource Desktop::getMainMouseSource() const noexcept                         { return MouseInputSource (mouseSources->sources.getUnchecked(0)); }
+void Desktop::beginDragAutoRepeat (int interval)                                      { mouseSources->beginDragAutoRepeat (interval); }
 
 //==============================================================================
 void Desktop::addFocusChangeListener    (FocusChangeListener* const listener)   { focusListeners.add (listener); }
diff --git a/modules/juce_gui_basics/layout/juce_ConcertinaPanel.cpp b/modules/juce_gui_basics/layout/juce_ConcertinaPanel.cpp
index f5dad1d1b1..73a29cf2b0 100644
--- a/modules/juce_gui_basics/layout/juce_ConcertinaPanel.cpp
+++ b/modules/juce_gui_basics/layout/juce_ConcertinaPanel.cpp
@@ -183,14 +183,14 @@ private:
     int getTotalSize (int start, const int end) const noexcept
     {
         int tot = 0;
-        while (start < end)  tot += get(start++).size;
+        while (start < end)  tot += get (start++).size;
         return tot;
     }
 
     int getMinimumSize (int start, const int end) const noexcept
     {
         int tot = 0;
-        while (start < end)  tot += get(start++).minSize;
+        while (start < end)  tot += get (start++).minSize;
         return tot;
     }
 
@@ -199,7 +199,7 @@ private:
         int tot = 0;
         while (start < end)
         {
-            const int mx = get(start++).maxSize;
+            const int mx = get (start++).maxSize;
             if (mx > 0x100000)
                 return mx;
 
@@ -429,9 +429,9 @@ void ConcertinaPanel::applyLayout (const PanelSizes& sizes, const bool animate)
 
     for (int i = 0; i < holders.size(); ++i)
     {
-        PanelHolder& p = *holders.getUnchecked(i);
+        PanelHolder& p = *holders.getUnchecked (i);
 
-        const int h = sizes.get(i).size;
+        const int h = sizes.get (i).size;
         const Rectangle<int> pos (0, y, w, h);
 
         if (animate)
diff --git a/modules/juce_gui_basics/layout/juce_FlexBox.cpp b/modules/juce_gui_basics/layout/juce_FlexBox.cpp
index e111300268..62f4f95340 100644
--- a/modules/juce_gui_basics/layout/juce_FlexBox.cpp
+++ b/modules/juce_gui_basics/layout/juce_FlexBox.cpp
@@ -31,10 +31,10 @@ struct FlexBoxLayoutCalculation
 {
     using Coord = double;
 
-    FlexBoxLayoutCalculation (const FlexBox& fb, Coord w, Coord h)
+    FlexBoxLayoutCalculation (FlexBox& fb, Coord w, Coord h)
        : owner (fb), parentWidth (w), parentHeight (h), numItems (owner.items.size()),
          isRowDirection (fb.flexDirection == FlexBox::Direction::row
-                          || fb.flexDirection == FlexBox::Direction::rowReverse),
+                      || fb.flexDirection == FlexBox::Direction::rowReverse),
          containerLineLength (isRowDirection ? parentWidth : parentHeight)
     {
         lineItems.calloc (numItems * numItems);
@@ -84,7 +84,7 @@ struct FlexBoxLayoutCalculation
         Coord crossSize, lineY, totalLength;
     };
 
-    const FlexBox& owner;
+    FlexBox& owner;
     const Coord parentWidth, parentHeight;
     const int numItems;
     const bool isRowDirection;
diff --git a/modules/juce_gui_basics/mouse/juce_SelectedItemSet.h b/modules/juce_gui_basics/mouse/juce_SelectedItemSet.h
index 19211b0157..5d0e0b2e1b 100644
--- a/modules/juce_gui_basics/mouse/juce_SelectedItemSet.h
+++ b/modules/juce_gui_basics/mouse/juce_SelectedItemSet.h
@@ -78,12 +78,12 @@ public:
                 if (! other.isSelected (selectedItems.getReference (i)))
                     itemDeselected (selectedItems.removeAndReturn (i));
 
-            for (SelectableItemType* i = other.selectedItems.begin(), *e = other.selectedItems.end(); i != e; ++i)
+            for (auto& i : selectedItems)
             {
-                if (! isSelected (*i))
+                if (! isSelected (i))
                 {
-                    selectedItems.add (*i);
-                    itemSelected (*i);
+                    selectedItems.add (i);
+                    itemSelected (i);
                 }
             }
         }
diff --git a/modules/juce_gui_basics/widgets/juce_Slider.cpp b/modules/juce_gui_basics/widgets/juce_Slider.cpp
index 71a3cca0e3..ad8c855c47 100644
--- a/modules/juce_gui_basics/widgets/juce_Slider.cpp
+++ b/modules/juce_gui_basics/widgets/juce_Slider.cpp
@@ -1121,7 +1121,7 @@ public:
                                                                        isVertical()   ? pixelPos : (owner.getHeight() / 2.0f)));
                 }
 
-                ms.setScreenPosition (mousePos);
+                const_cast <MouseInputSource&> (ms).setScreenPosition (mousePos);
             }
         }
     }
diff --git a/modules/juce_osc/osc/juce_OSCBundle.cpp b/modules/juce_osc/osc/juce_OSCBundle.cpp
index e2041834d6..c5c47192e5 100644
--- a/modules/juce_osc/osc/juce_OSCBundle.cpp
+++ b/modules/juce_osc/osc/juce_OSCBundle.cpp
@@ -195,15 +195,15 @@ private:
         expect (! bundle[1].isBundle());
 
         int numElementsCounted = 0;
-        for (OSCBundle::Element* element = bundle.begin(); element != bundle.end(); ++element)
+        for (auto& element : bundle)
         {
-            expect (element->isMessage());
-            expect (! element->isBundle());
+            expect (element.isMessage());
+            expect (! element.isBundle());
             ++numElementsCounted;
         }
         expectEquals (numElementsCounted, 2);
 
-        OSCBundle::Element* e = bundle.begin();
+        auto* e = bundle.begin();
         expect (e[0].getMessage().size() == 1);
         expect (e[0].getMessage().begin()->getInt32() == testInt);
         expect (e[1].getMessage().size() == 2);
diff --git a/modules/juce_osc/osc/juce_OSCBundle.h b/modules/juce_osc/osc/juce_OSCBundle.h
index b3b0d4861e..e9c302ac09 100644
--- a/modules/juce_osc/osc/juce_OSCBundle.h
+++ b/modules/juce_osc/osc/juce_OSCBundle.h
@@ -111,7 +111,12 @@ public:
         This method does not check the range and results in undefined behaviour
         in case i < 0 or i >= size().
     */
-    OSCBundle::Element& operator[] (const int i) const noexcept
+    OSCBundle::Element& operator[] (const int i) noexcept
+    {
+        return elements.getReference (i);
+    }
+
+    const OSCBundle::Element& operator[] (const int i) const noexcept
     {
         return elements.getReference (i);
     }
diff --git a/modules/juce_osc/osc/juce_OSCMessage.cpp b/modules/juce_osc/osc/juce_OSCMessage.cpp
index 6bb21cef21..994d954bd6 100644
--- a/modules/juce_osc/osc/juce_OSCMessage.cpp
+++ b/modules/juce_osc/osc/juce_OSCMessage.cpp
@@ -53,7 +53,12 @@ bool OSCMessage::isEmpty() const noexcept
     return arguments.isEmpty();
 }
 
-OSCArgument& OSCMessage::operator[] (const int i) const noexcept
+OSCArgument& OSCMessage::operator[] (const int i) noexcept
+{
+    return arguments.getReference (i);
+}
+
+const OSCArgument& OSCMessage::operator[] (const int i) const noexcept
 {
     return arguments.getReference (i);
 }
diff --git a/modules/juce_osc/osc/juce_OSCMessage.h b/modules/juce_osc/osc/juce_OSCMessage.h
index 1d2f7fcf7e..117d3bcb95 100644
--- a/modules/juce_osc/osc/juce_OSCMessage.h
+++ b/modules/juce_osc/osc/juce_OSCMessage.h
@@ -93,7 +93,8 @@ public:
         This method does not check the range and results in undefined behaviour
         in case i < 0 or i >= size().
     */
-    OSCArgument& operator[] (const int i) const noexcept;
+    OSCArgument& operator[] (const int i) noexcept;
+    const OSCArgument& operator[] (const int i) const noexcept;
 
     /** Returns a pointer to the first OSCArgument in the OSCMessage object.
         This method is provided for compatibility with standard C++ iteration mechanisms.
@@ -108,7 +109,6 @@ public:
     /** Removes all arguments from the OSCMessage. */
     void clear();
 
-
     //==============================================================================
     /** Creates a new OSCArgument of type int32 with a given value
         and adds it to the OSCMessage object.