8 #import <Foundation/Foundation.h>
15 @property (nonatomic, readonly) BOOL
isEmpty;
24 @property (nonatomic, readonly)
int value;
30 + (nonnull instancetype)
empty;
37 + (nonnull instancetype)of:(
int)aValue;
49 @property (nonatomic, readonly) BOOL
isEmpty;
57 @property (nonatomic, readonly)
unsigned int value;
63 + (nonnull instancetype)
empty;
70 + (nonnull instancetype)of:(
unsigned int)aValue;
82 @property (nonatomic, readonly) BOOL
isEmpty;
90 @property (nonatomic, readonly) BOOL
value;
96 + (nonnull instancetype)
empty;
103 + (nonnull instancetype)of:(BOOL)aValue;
125 @property (nonatomic, readonly)
double value;
131 + (nonnull instancetype)
empty;
138 + (nonnull instancetype)of:(
double)aValue;