Useful category for delegates. WARNING: it's not finished yet.

NSObject+YKSafeSelector.h

#import <Foundation/Foundation.h>

@interface NSObject (YKSafeSelector)

- (void)safeSelector:(SEL)selector, ... NS_REQUIRES_NIL_TERMINATION;

@end

NSObject+YKSafeSelector.m

#import "NSObject+YKSafeSelector.h"

@implementation NSObject (YKSafeSelector)

- (void)safeSelector:(SEL)selector, ...
{
    if (![self respondsToSelector:selector])
        return;
    NSInvocation *inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:selector]];
    [inv setSelector:selector];
    [inv setTarget:self];
    
    va_list argumentList;
    if (selector) {
        va_start(argumentList, (SEL)selector);
        NSInteger idx = 2;
        id eachObject = nil;
        while ((eachObject = va_arg(argumentList, id))){
            [inv setArgument:(__bridge void *)(eachObject) atIndex:idx];
            idx++;
            
        }
        va_end(argumentList);
    }
    [inv invoke];
}

@end