rehash of callSelector

gistfile1.m

- (void)makeObjectsPerformSelector:(SEL)aSelector argumentAddresses:(void *)arg1, ...
{
#define kMaximumCallSelectorArguments 20
    
    // if there's nothing in here, GTFO.
    if (self.count == 0)
        return;
    
    id sampleTarget = [self objectAtIndex:0];
    NSMethodSignature *methodSig = [[sampleTarget class] instanceMethodSignatureForSelector:aSelector];
    NSUInteger numberOfArguments = [methodSig numberOfArguments] - 2;
    
    if (numberOfArguments >= kMaximumCallSelectorArguments)
        [NSException raise:@"SDException" format:@"makeObjectsPerformSelector:argumentAddresses: cannot take more than %i arguments.", kMaximumCallSelectorArguments];
    
    void *arguments[kMaximumCallSelectorArguments];
    memset(arguments, 0, sizeof(void *) * kMaximumCallSelectorArguments);
    
    va_list args;
    va_start(args, arg1);
    
    arguments[0] = arg1;
    for (NSUInteger i = 1; i < numberOfArguments; i++)
        arguments[i] = va_arg(args, void *);
    
    va_end(args);
    
    NSArray *copyOfSelf = [self copy];

    for (NSObject *object in copyOfSelf)
        if([object respondsToSelector:aSelector])
        {
            NSInvocation *invocation = [NSInvocation invocationWithMethodSignature: methodSig];
            [invocation setTarget:object];
            [invocation setSelector:aSelector];

            void *theArg = nil;
            for (NSUInteger i = 0; i < numberOfArguments; i++)
            {
                theArg = arguments[i];
                [invocation setArgument:theArg atIndex:i + 2];
            }
            
            [invocation invoke];
        }
}