Fix warnings when building in C++20 mode

examples/Plugins/InterAppAudioEffectPluginDemo.h

@@ -176,6 +176,8 @@ public:
         return true;
     }
 
+    using AudioProcessor::processBlock;
+
     void processBlock (AudioBuffer<float>& buffer, MidiBuffer&) override
     {
         float gain = *parameters.getRawParameterValue ("gain");
@@ -423,8 +425,8 @@ private:
         //==============================================================================
         bool transportControllable()
         {
-            auto playHead = iaaEffectProcessor.getPlayHead();
-            return playHead != nullptr && playHead->canControlTransport();
+            auto processorPlayHead = iaaEffectProcessor.getPlayHead();
+            return processorPlayHead != nullptr && processorPlayHead->canControlTransport();
         }
 
         //==============================================================================

examples/Plugins/SamplerPluginDemo.h

@@ -2344,7 +2344,7 @@ public:
             std::vector<std::unique_ptr<MPESamplerVoice>> newVoices;
         };
 
-        numberOfVoices = std::min (maxVoices, numberOfVoices);
+        numberOfVoices = std::min ((int) maxVoices, numberOfVoices);
         auto loadedSamplerSound = samplerSound;
         std::vector<std::unique_ptr<MPESamplerVoice>> newSamplerVoices;
         newSamplerVoices.reserve ((size_t) numberOfVoices);
@@ -2595,12 +2595,10 @@ private:
     // with the real state of the processor.
     SpinLock commandQueueMutex;
 
-    static constexpr auto maxVoices { 20 };
+    enum { maxVoices = 20 };
 
     // This is used for visualising the current playback position of each voice.
     std::array<std::atomic<float>, maxVoices> playbackPositions;
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SamplerAudioProcessor)
 };
-
-const int SamplerAudioProcessor::maxVoices;

modules/juce_audio_plugin_client/AU/juce_AU_Wrapper.mm

@@ -47,7 +47,8 @@ JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wshorten-64-to-32",
                                      "-Wzero-as-null-pointer-constant",
                                      "-Wnullable-to-nonnull-conversion",
                                      "-Wgnu-zero-variadic-macro-arguments",
-                                     "-Wformat-pedantic")
+                                     "-Wformat-pedantic",
+                                     "-Wdeprecated-anon-enum-enum-conversion")
 
 #include "../utility/juce_IncludeSystemHeaders.h"
 
@@ -354,7 +355,7 @@ public:
                     }
                 }
 
-                err = (busNr == (requestedNumBus - 1) ? noErr : kAudioUnitErr_FormatNotSupported);
+                err = (busNr == (requestedNumBus - 1) ? (OSStatus) noErr : (OSStatus) kAudioUnitErr_FormatNotSupported);
             }
 
             // was there an error?
@@ -1902,7 +1903,7 @@ private:
 
         return (scope != kAudioUnitScope_Input
              && scope != kAudioUnitScope_Output)
-              ? kAudioUnitErr_InvalidScope : noErr;
+              ? (OSStatus) kAudioUnitErr_InvalidScope : (OSStatus) noErr;
     }
 
     OSStatus elementToBusIdx (AudioUnitScope scope, AudioUnitElement element, bool& isInput, int& busIdx) noexcept

modules/juce_audio_plugin_client/juce_audio_plugin_client_AU_2.mm

@@ -46,7 +46,9 @@ JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wparentheses",
                                      "-Wnullable-to-nonnull-conversion",
                                      "-Wignored-qualifiers",
                                      "-Wfour-char-constants",
-                                     "-Wmissing-prototypes")
+                                     "-Wmissing-prototypes",
+                                     "-Wdeprecated-anon-enum-enum-conversion",
+                                     "-Wambiguous-reversed-operator")
 
 // From MacOS 10.13 and iOS 11 Apple has (sensibly!) stopped defining a whole
 // set of functions with rather generic names. However, we still need a couple

modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm

@@ -758,7 +758,7 @@ public:
                         zerostruct (stream); // (can't use "= { 0 }" on this object because it's typedef'ed as a C struct)
                         stream.mSampleRate       = sampleRate;
                         stream.mFormatID         = kAudioFormatLinearPCM;
-                        stream.mFormatFlags      = kAudioFormatFlagsNativeFloatPacked | kAudioFormatFlagIsNonInterleaved | kAudioFormatFlagsNativeEndian;
+                        stream.mFormatFlags      = (int) kAudioFormatFlagsNativeFloatPacked | (int) kAudioFormatFlagIsNonInterleaved | (int) kAudioFormatFlagsNativeEndian;
                         stream.mFramesPerPacket  = 1;
                         stream.mBytesPerPacket   = 4;
                         stream.mBytesPerFrame    = 4;

modules/juce_audio_processors/utilities/juce_AudioProcessorValueTreeState.cpp

@@ -162,7 +162,7 @@ private:
             return;
 
         unnormalisedValue = newValue;
-        listeners.call ([=] (Listener& l) { l.parameterChanged (parameter.paramID, unnormalisedValue); });
+        listeners.call ([this] (Listener& l) { l.parameterChanged (parameter.paramID, unnormalisedValue); });
         listenersNeedCalling = false;
         needsUpdate = true;
     }

modules/juce_graphics/native/juce_mac_CoreGraphicsContext.mm

@@ -171,9 +171,9 @@ private:
     static CGBitmapInfo getCGImageFlags (const Image::PixelFormat& format)
     {
        #if JUCE_BIG_ENDIAN
-        return format == Image::ARGB ? (kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big) : kCGBitmapByteOrderDefault;
+        return format == Image::ARGB ? ((uint32_t) kCGImageAlphaPremultipliedFirst | (uint32_t) kCGBitmapByteOrder32Big) : kCGBitmapByteOrderDefault;
        #else
-        return format == Image::ARGB ? (kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little) : kCGBitmapByteOrderDefault;
+        return format == Image::ARGB ? ((uint32_t) kCGImageAlphaPremultipliedFirst | (uint32_t) kCGBitmapByteOrder32Little) : kCGBitmapByteOrderDefault;
        #endif
     }
 

modules/juce_gui_basics/components/juce_Component.cpp

@@ -1181,7 +1181,12 @@ void Component::sendMovedResizedMessages (bool wasMoved, bool wasResized)
         parentComponent->childBoundsChanged (this);
 
     if (! checker.shouldBailOut())
-        componentListeners.callChecked (checker, [=] (ComponentListener& l) { l.componentMovedOrResized (*this, wasMoved, wasResized); });
+    {
+        componentListeners.callChecked (checker, [this, wasMoved, wasResized] (ComponentListener& l)
+        {
+            l.componentMovedOrResized (*this, wasMoved, wasResized);
+        });
+    }
 }
 
 void Component::setSize (int w, int h)                  { setBounds (getX(), getY(), w, h); }

modules/juce_gui_basics/layout/juce_ScrollBar.cpp

@@ -173,7 +173,7 @@ void ScrollBar::removeListener (Listener* listener)
 void ScrollBar::handleAsyncUpdate()
 {
     auto start = visibleRange.getStart(); // (need to use a temp variable for VC7 compatibility)
-    listeners.call ([=] (Listener& l) { l.scrollBarMoved (this, start); });
+    listeners.call ([this, start] (Listener& l) { l.scrollBarMoved (this, start); });
 }
 
 //==============================================================================