Is it possible to iterate a masked enum in objective c - objective-c

Question

I've seen that this is possible in other languages but need something like this in objective-c
I have an enum similar to this
typedef enum {
option1 = 1 << 0,
option2 = 1 << 1,
option3 = 1 << 2
...
...
} SomePossibleOptions;
and then a user can create a mask of the wanted options
SomePossibleOptions myOptions = option1 | option2;
[self.someObject performOperationsForOptions:myOptions];
-(void)performOperationsForOptions:(SomePossibleOptions)theOptions
{
if (myOptions & option1)
{
// do something
}
if (myOptions & option2
{
// do something
}
//(could use a switch statement)
}
But would much rather use some sort of syntax
foreach (option in myoption)
{
//do something
}

Answer 1

Sometimes I use a last value in my normal enums called "SomeEnumCount", which then has exactly the number of items I have in the enum, so I can make a loop for that.
In your case it would be something like this:
typedef enum {
option1 = 1 << 0,
option2 = 1 << 1,
option3 = 1 << 2,
...
...
optionCount = 1 << n
} SomePossibleOptions;
Or maybe you can call it OptionNone, if you have one like that, and that would be always the last one.
And to make a loop you have to make something like this
NSInteger optionsCount = (int)log2(optionCount);
for (NSInteger i = 0; i < optionsCount; i++) {
SomePossibleOptions option = (SomePossibleOptions)(1 << i);
//handle your options here
}
I hope it helps!
EDIT: Maybe I misunderstood the question. If you want to loop on just the options that are masked together, you should write a function, based on the above. Something like:
- (NSArray *)optionsInMask:(SomePossibleOptions)maskedOptions {
NSMutableArray * options = [NSMutableArray array];
NSInteger optionsCount = (int)log2(optionCount);
for (NSInteger i = 0; i < optionsCount; i++) {
SomePossibleOptions option = (SomePossibleOptions)(1 << i);
if (maskedOptions & option) {
[options addObject:[NSValue valueWithInteger:option]];
}
}
return [NSArray arrayWithArray:options];
}
And then you can loop it like:
for (NSValue * value in [self optionsInMask:myOptions]) {
SomePossibleOption option = (SomePossibleOptions)[value integerValue];
//your code here
}