Check that a bitmask flag is zero

Asked Feb 03 '15 at 07:19

Active Feb 03 '15 at 07:58

Viewed 57 times

I'm getting data from a server. The first bit indicates whether a message was read or not read: 1 for "read" and 0 for "not read". The second bit says whether the message was edited or not.

So I'm trying to read the statuses:

typedef NS_ENUM(NSUInteger, MessageStatus) {
    MessageStatusReaded   = (1 << 0), // => 00000001
    MessageStatusEdited   = (1 << 1), // => 00000010
};

But I don't understand how to check zero values (for not read and not edited).

edited Feb 03 '15 at 07:58

jscs

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asked Feb 03 '15 at 07:19

Maria

2

put an enum `MessageStatusNone = 0` ? – Fonix Feb 03 '15 at 07:36
but I need at least two more statuses - MessageStatusNotRead and MessageStatusNotEdited. – Maria Feb 03 '15 at 07:47

Check that a bitmask flag is zero

0 Answers0