Exception thrown in NSOrderedSet generated accessors

Question

On my Lion app, I have this data model:

The relationship subitem

Answer 1

I think everybody is missing the real problem. It is not in the accessor methods but rather in the fact that NSOrderedSet is not a subclass of NSSet. So when -interSectsSet: is called with an ordered set as argument it fails.

NSOrderedSet* setA = [NSOrderedSet orderedSetWithObjects:@"A",@"B",@"C",nil];
NSSet* setB = [NSSet setWithObjects:@"C",@"D", nil];

 [setB intersectsSet:setA];

fails with *** -[NSSet intersectsSet:]: set argument is not an NSSet

Looks like the fix is to change the implementation of the set operators so they handle the types transparently. No reason why a -intersectsSet: should work with either an ordered or unordered set.

The exception happens in the change notification. Presumably in the code that handles the inverse relationship. Since it only happens if I set an inverse relationship.

The following did the trick for me

@implementation MF_NSOrderedSetFixes

+ (void) fixSetMethods
{
    NSArray* classes = [NSArray arrayWithObjects:@"NSSet", @"NSMutableSet", @"NSOrderedSet", @"NSMutableOrderedSet",nil];

    [classes enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        NSString* name = obj;
        Class aClass = objc_lookUpClass([name UTF8String]);
        [MF_NSOrderedSetFixes fixMethodWithSetArgument:@selector(intersectsSet:) forClass:aClass];
        [MF_NSOrderedSetFixes fixMethodWithSetArgument:@selector(isSubsetOfSet:) forClass:aClass];
    }];
}

typedef BOOL (*BoolNSetIMP)(id _s,SEL sel, NSSet*);

/*
    Works for all methods of type - (BOOL) method:(NSSet*) aSet
*/
+ (void) fixMethodWithSetArgument:(SEL) aSel forClass:(Class) aClass 
{
    /* Check that class actually implements method first */
    /* can't use get_classInstanceMethod() since it checks superclass */
    unsigned int count,i;
    Method method = NULL;
    Method* methods = class_copyMethodList(aClass, &count);
    if(methods) {
        for(i=0;i