The MPESynthesiser::renderNextBlock template is not working in Xcode 11.3.1

Why can’t I inherit from AudioProcessor and MPESynthesiser? If I do, a call to MPESynthesiserBase::renderNextBlock does nothing. If I edit the juce code to make MPESynthesiserBase::renderNextBlock not a template function, it works.

Is there something with multiple inheritance and template functions? Or is this a bug in Xcode?

The MPESynthesiser::renderNextBlock template is not working / generating valid code using Xcode 11.3.1.

To reproduce, build the SamplerPluginDemo.h PIP. Load in AudioPluginHost. It will immediately throw asserts about invalid MIDI even though no MIDI coming in. It is impossible to step into renderNextBlock. Changing renderNextBlock to not be a template fixes the issue. Or moving the function definition to the header fixes it as well.

Ok, I’ve split it into its own class and it still doesn’t work, so it’s not a multiple inheritance issue.

I’ve used MPESynthesiser before with no issues, not sure why it’s not working now.