[Ron]

I’ve just started using Felgo (and Qt6) after a long time using Qt5. My code needs to use some native MacOS frameworks, most notably CoreMIDI. I’ve used this code for years in Qt5 apps, but now when I try to compile, I get errors like this:

rtmidi/RtMidi.h:633: error: In included file: non-defining declaration of enumeration with a fixed underlying type is only permitted as a standalone declaration; missing list of enumerators?

I can follow these errors through several layers of #includes to Apple’s headers, such as CoreFoundation/CFBase.h, where I see that definitions like this are the cause:

typedef CF_ENUM(CFIndex, CFComparisonResult) {
    kCFCompareLessThan = -1L,
    kCFCompareEqualTo = 0,
    kCFCompareGreaterThan = 1
};

In doing some digging, it seems like the macro used here by Apple uses some non-standard enum definition that Clang used to accept without trouble, but now causes an error.

I figure that you folks at Felgo had to have run into this at some point. I see that this error can be disabled with the -Wno-elaborated-enum-base flag, but I’m not typically a fan of “just turn off the warning” types of “solutions”. How are others handling this issue?

 

[GüntherFelgo Team]

Hi Ron,

I am not aware that we ran into this specific issue with the native Frameworks that Felgo integrates with.
Do you maybe include the Framework header from a *.cpp file, instead of a .mm file (objective-c file)? I can imagine this could make a difference, but just a guess.

Best,
Günther

[Ron]

Hmm. There’s definitely no Objective C in my project, but I’ve been compiling this C++ code for 10+ years and it’s been fine until now. For now, I’ve tried turning off the warning and so far it’s working, but I’ll try to find a more reassuring solution.