Simple mask iteration. Does not care about subsets.

gistfile1.m

// Use NS_OPTIONS for some compiler sugar.
//
// Use a type that fits your struct but consider using 
// types directly to avoid 32/64bit width inconsistencies. 

typedef NS_OPTIONS(UInt16, MaskType) {
    MaskTypeOptionNone = 0,
    MaskTypeOptionOne = 1 << 0,
    MaskTypeOptionTwo = 1 << 1,
};


- (void)iterateOverBitmask:(MaskType)mask {
    for (NSInteger i = 0; i <= (sizeof(MaskType) * 8); i++) {
    
        // You may use currentBit as if it was mask with only the one bit set
        MaskType currentBit = (1 << i);
        if ((mask & currentBit)) {
        
            // Hit! 
            
        } else {
        
            // Miss :-(
            
        }
    }
}