Wrap C primitive values in CFArray of CFNumbers

Question

What is the best way to implement a method to wrap a C array of primitive numbers into a CFArray of CFNumbers?

I want to call something like:

double values[] = {1.2345, 678.9};
CFArrayRef arr = NumberWrappedValuesArray(&values, 2, kCFNumberDoubleType);

And tried this:

CFArrayRef NumberWrappedValuesArray(void * valueArrayPtr, CFIndex count, CFNumberType numberType) {
    CFMutableArrayRef array = CFArrayCreateMutable(NULL, count, &kCFTypeArrayCallBacks);

    for (int i = 0; i < count; i++) {
        CFNumberRef numberWrappedValue = CFNumberCreate(NULL, numberType, &valueArrayPtr[i]);
        CFArrayAppendValue(array, numberWrappedValue);
        CFRelease(numberWrappedValue);
    }

    CFRelease(array);
    return array;
}

1. It doesn't work (returned array has 0 elements), why and how do I fix it?
2. Is there a more elegant way, potentially avoiding the mutable CFArray?

Thanks!

Answer 1

You can use CFArrayCreate.

Example:

CFArrayRef NumberWrappedValuesArray(void *valueArrayPtr, size_t size, CFIndex count, CFNumberType numberType) {
    size_t i, n;
    CFArrayRef ret;
    CFNumberRef *ref = malloc(sizeof(CFNumberRef) * count);

    /* create array of boxed types. */
    for (i = 0, n = count; i < n; ++i)
        ref[i] = CFNumberCreate(NULL, numberType, ((char *)valueArrayPtr) + (size * i));

    /* create CFArray. */
    ret = CFArrayCreate(NULL, (const void **)ref, count, &kCFTypeArrayCallBacks);

    /* release boxed types and malloc'ed array. */
    for (i = 0; i < n; ++i)
        CFRelease(ref[i]);
    free(ref);

    /* return CFArray, without releasing first! Has to be done by the caller. */
    return ret;
}

Error handling omitted for clarity.