cfauto.c

#define CF_AUTORELEASED __attribute__ ((cleanup(CFReleaseCleanup)))
static inline void CFReleaseCleanup(CF_CONSUMED void *objPtr) {
    CFRelease(*(CFTypeRef *)objPtr);
}

usage.c

- (CGSize)sizeThatFits
{
    CF_AUTORELEASED CTFramesetterRef framesetter = [self _createFramesetter];
    return [self sizeThatFitsFrameSetter:framesetter];
}

// as opposed to

- (CGSize)sizeThatFits
{
    CTFramesetterRef framesetter = [self _createFramesetter];
    CGSize const size = [self sizeThatFitsFrameSetter:framesetter];
    CFRelease(framesetter);
    return size
}