Birthday celebration

gistfile1.m

//GCD way:

double delayInSeconds = (24 * 60) * 60;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    [self setAge:[self age] + 1];
});


//NSInvocation way:

//We can't simply call [self performSelector:@selector(setAge:) withObject:[self age] + 1 afterDelay:(24 * 60) * 60]
//because the withObject: argument only accepts an "id" - le sigh.

NSMethodSignature *signature = [self methodSignatureForSelector:@selector(setAge:)];
NSInvocation *inv = [NSInvocation invocationWithMethodSignature:signature];

char newAge = [self age] + 1; //we don't live more than 127 years, do we?

[inv setArgument:&newAge
         atIndex:0];

[inv performSelector:@selector(invokeWithTarget:) withObject:self afterDelay:(24 * 60) * 60];

//Happy birthday to me! :)