Obj-C Generics Example

GenericsExampleForObjC.h

// I borrowed pieces of this from the generics implementations in FaceBook's Bolts Framework and the Parse SDK

@import Foundation;

@class GRGCollectionItemTypeClass<__covariant CodableCollectionItem:NSObject<NSCopying,NSSecureCoding> *>;


@interface GRGCollectionClass<__covariant CodableCollectionItem:NSObject<NSCopying,NSSecureCoding> *> : NSObject<NSFastEnumeration>

typedef BOOL(^GRGNextCollectionItemBlock)(GRGCollectionItemTypeClass<CodableCollectionItem> *nextItem);

@property (nullable,nonatomic,copy) GRGNextCollectionItemBlock onRunNextItem;

@end