Create a NSSet from NSArray based on property

Question

How does one create a NSSet of objects from an array based on a property.

e.g. Array of objects, each with a strong reference to a type pro

Answer 1

NSMutableSet* classes = [[NSMutableSet alloc] init];
NSMutableSet* actualSet = [[NSMutableSet alloc] init];

for(id object in array) {
    if([classes containsObject:[object class]] == NO) {
        [classes addObject:[object class]];
        [actualSet addObject:object];
    }        
}