As I understand it, anything created with an alloc, new, or copy needs to be manually released. For example:
int main(void) {
NSString *string;
string = [[NSString alloc] init];
/* use the string */
[string release];
}
My question, though, is wouldn't this be just as valid?:
int main(void) {
NSAutoreleasePool *pool;
pool = [[NSAutoreleasePool alloc] init];
NSString *string;
string = [[[NSString alloc] init] autorelease];
/* use the string */
[pool drain];
}
Yes, your second code snippit is perfectly valid.
Every time -autorelease is sent to an object, it is added to the inner-most autorelease pool. When the pool is drained, it simply sends -release to all the objects in the pool.
Autorelease pools are simply a convenience that allows you to defer sending -release until "later". That "later" can happen in several places, but the most common in Cocoa GUI apps is at the end of the current run loop cycle.