NSError

http://atmarkplant-dj.blogspot.jp/2013/02/nserror-osstatus.html

+(BOOL)errorLog:(NSError *)error message:(NSString *)message
{
    if ( error != nil )
    {
        NSLog(@"%@ : %@", message, [error localizedDescription]);
    }
    return error == nil;
}
+(BOOL)statusLog:(OSStatus)status message:(NSString *)message
{
    if ( status != noErr )
    {
        NSLog(@"Error - %@ %ld", message, status);
    }
    return status == noErr;
}