Class objects in id variables will respond to selectors that are the same as instance method names.

ClassyDelegate.m

#import <Foundation/Foundation.h>

@interface Deleg : NSObject

+ (void)delegatorDidSomething;
- (void)delegatorDidSomething;

@end

@implementation Deleg

+ (void)delegatorDidSomething
{
    NSLog(@"Classy");
}

- (void)delegatorDidSomething
{
    NSLog(@"Instantaneous");
}

@end

int main(int argc, const char * argv[])
{

    @autoreleasepool {
        
        id c = [Deleg class];
        id i = [Deleg new];
        
        NSCAssert([c respondsToSelector:@selector(delegatorDidSomething)],
                  @"Class object does not respond");
        [c delegatorDidSomething];
        NSCAssert([i respondsToSelector:@selector(delegatorDidSomething)],
                  @"Instance does not respond");
        [i delegatorDidSomething];
        
    }
    return 0;
}