Question

I’m trying to achieve [NSMutableDictionary dictionaryWithObjects:frames forKeys:items] but with a CFDictionary so I have control over the key and value callbacks. This is what I’ve got:

__unsafe_unretained id keys[itemCount];
[items getObjects:keys range:NSMakeRange(0, itemCount)];
__unsafe_unretained id values[itemCount];
[frames getObjects:values range:NSMakeRange(0, itemCount)];
CFDictionaryCreate(kCFAllocatorDefault, (const void **)keys, (const void **)values, itemCount, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);

Which gives the following error: Cast of an indirect pointer to an Objective-C pointer to 'const void **' is disallowed with ARC.

I’ve tried various permutations of bridging, but I can’t seem to get it to compile without complaint.

Any help much appreciated!

Answer 1

I haven’t been able to find a syntax for that either. (EDIT: Justin’s answer has the syntax.) Try this instead:

void *keys[itemCount];
[items getObjects:(__unsafe_unretained id *)(void *)keys range:NSMakeRange(0, itemCount)];

Then you don’t need a cast when you call CFDictionaryCreate.