Obj-C enum “Incompatible Types in initialization”

Question

I'm having a problem with enum type initialization that appears to be simple to solve but I haven't figured out how to do it. Suppose I declare the following enum type:

typedef enum NXSoundType {
    NXSoundTypeNone,
    NXSoundTypeEffect,
    NXSoundTypeBackgroundMusic
} NXSoundType;

I declare a convenience method for returning one of the NXSoundType enum types given a NSString object like this (NOTE: NXSound is an object that contains a NXSoundType attribute named "type"):

- (NXSoundType)nxSoundTypeFromIdentifier:(NSString*)nxSoundIdentifier {
    NXSoundType type = NXSoundTypeNone;

    for (NXSound *nxSound in self.nxSounds) {
        if ([nxSound.identifier isEqualToString:nxSoundIdentifier]) {
            type = nxSound.type;
        }
    }    
    return type;
}

So far, so well. But the following call is not working:

NXSoundType type = [self nxSoundTypeFromIdentifier:@"kNXTargetGameSoundIdEffectTic"];

What's wrong? Thank you in advance.

Answer 1

I solved the problem. Despite the compiler error message, the problem was not related to wrong enum type declaration/initialization. The problem was that the method

- (NXSoundType)nxSoundTypeFromIdentifier:(NSString*)nxSoundIdentifier;

was defined as a private method in a base-class and was been called by a sub-class. In this way, due to the Obj-C dynamic nature, it was expected to return an id which cannot be assigned to the NXSoundType enum (only to objects). A simple cast removed the problem, the solution was to change the method call to:

NXSoundType type = (NXSoundType)[self nxSoundTypeFromIdentifier:@"kNXTargetGameSoundIdEffectTic"];

Appreciate all replies and sorry for any confusion. Hope this helps somebody.

Answer 2

Try using just:

typedef enum {
    NXSoundTypeNone,
    NXSoundTypeEffect,
    NXSoundTypeBackgroundMusic
} NXSoundType;

and see if that helps. having the typedef and name be the same might be confusing Obj-C compiler like this person's question.