How to transfer ownership out of an @autoreleasepool with ARC

Question

I have the following code

- (NSString *)stringByEscapingXMLEntities;
{   
    NSString *result;
    @autoreleasepool {
        result = [self stringByReplacingOccurrencesOfString:@"&" withString:@"&"];
        result = [result stringByReplacingOccurrencesOfString:@"\"" withString:@"""];
        // ... lot of -stringByReplacingOccurrencesOfString: calls
        result = [result stringByReplacingOccurrencesOfString:@" " withString:@" "];
    }
    return result;
}

I ask myself now how would I transfer ownership result out of the method. Before ARC I would have retained result before exiting the autorelease block and returned it autoreleased at the end of the method.

Thanks!

Answer 1

There are two ways to do that:

• Rename the method to something like copyStringByEscapingXMLEntities -- the copy indicates the transfer of ownership and ARC creates the code accordingly.
• Append, in the header, NS_RETURNS_RETAINED to the method definition like this: - (NSString *)stringByEscapingXMLEntities NS_RETURNS_RETAINED.

---

EDIT: As 'iljawascoding' mentioned, the @autoreleasepool has no real need to be kept around -- except for optimization.

---

EDIT 2: And remember: ARC always does the right thing. All the things you tried (your comment) result in the very same correct program -- albeit with the lack of some optimization if result was defined as __strong.