Add C pointer to NSMutableArray

Question

I am writing an Objective-C program that deals with low level image memory. I am using ANSI-C structs for my data storage -- Full blown objects seem overkill seeing as the data I am storing is 100% data, with no methods to operate on that data. Specifically, I am writing a customizable posterization algorithm which relies on an array of colors -- This is where things get tricky. I am storing my colors as structs of three floats, and an integer flag (related to the posterization algorithm specifically). Everyhting is going well, except for one thing...

[actual question]

I can't figure out how to add pointers to an NSMutableArray! I know how to add an object, but adding a pointer to a struct seems to be more difficult -- I do not want NSMutableArray dereferencing my pointer and treating the struct as some sort of strange object. I want NSMutableArray to add the pointer its self to its collection. How do I go about doing this?

Thanks in advance,

G

Answer 1

There's a class designed precisely for this: NSPointerArray. See Apple's docs here. For arbitrary pointers, you'll probably want to use the NSPointerFunctionsOpaqueMemory and NSPointerFunctionsOpaquePersonality options.

If NSPointerArray is not available (for example, if you're developing for iOS), then you could wrap your pointers using -[NSValue valueWithPointer:], as long as the overhead of wrapping & unwrapping doesn't prove too slow.