NSObject.h

@protocol NSCopying

- (id)copyWithZone:(NSZone *)zone;

@end

@protocol NSMutableCopying

- (id)mutableCopyWithZone:(NSZone *)zone;

@end

#pragma mark - 归档协议
@protocol NSCoding

- (void)encodeWithCoder:(NSCoder *)aCoder;  // 归档
- (id)initWithCoder:(NSCoder *)aDecoder;    // 解挡

@end


@protocol NSSecureCoding <NSCoding>

@required

+ (BOOL)supportsSecureCoding;

@end

#prama mark - 基类
@interface NSObject (NSCoderMethods)

+ (NSInteger)version;
+ (void)setVersion:(NSInteger)aVersion;
- (Class)classForCoder;
- (id)replacementObjectForCoder:(NSCoder *)aCoder;
- (id)awakeAfterUsingCoder:(NSCoder *)aDecoder NS_REPLACES_RECEIVER;

@end


/***********    Discardable Content     ***********/

@protocol NSDiscardableContent
@required
- (BOOL)beginContentAccess;
- (void)endContentAccess;
- (void)discardContentIfPossible;
- (BOOL)isContentDiscarded;
@end

@interface NSObject (NSDiscardableContentProxy)
- (id)autoContentAccessingProxy NS_AVAILABLE(10_6, 4_0);
@end


/***********    Object Allocation / Deallocation        *******/
    
FOUNDATION_EXPORT id NSAllocateObject(Class aClass, NSUInteger extraBytes, NSZone *zone) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

FOUNDATION_EXPORT void NSDeallocateObject(id object) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

FOUNDATION_EXPORT id NSCopyObject(id object, NSUInteger extraBytes, NSZone *zone) NS_AUTOMATED_REFCOUNT_UNAVAILABLE NS_DEPRECATED(10_0, 10_8, 2_0, 6_0);

FOUNDATION_EXPORT BOOL NSShouldRetainWithZone(id anObject, NSZone *requestedZone) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

FOUNDATION_EXPORT void NSIncrementExtraRefCount(id object) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

FOUNDATION_EXPORT BOOL NSDecrementExtraRefCountWasZero(id object) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

FOUNDATION_EXPORT NSUInteger NSExtraRefCount(id object) NS_AUTOMATED_REFCOUNT_UNAVAILABLE;

#if __has_feature(objc_arc)

// After using a CFBridgingRetain on an NSObject, the caller must take responsibility for calling CFRelease at an appropriate time.
NS_INLINE CF_RETURNS_RETAINED CFTypeRef CFBridgingRetain(id X) {
    return (__bridge_retained CFTypeRef)X;
}

NS_INLINE id CFBridgingRelease(CFTypeRef CF_CONSUMED X) {
    return (__bridge_transfer id)X;
}

#else

// This function is intended for use while converting to ARC mode only.
NS_INLINE CF_RETURNS_RETAINED CFTypeRef CFBridgingRetain(id X) {
    return X ? CFRetain((CFTypeRef)X) : NULL;
}

// This function is intended for use while converting to ARC mode only.
NS_INLINE id CFBridgingRelease(CFTypeRef CF_CONSUMED X) {
    return [(id)CFMakeCollectable(X) autorelease];
}

#endif

#pragma mark - 模拟器自带头文件

@class NSString, NSMethodSignature, NSInvocation;

@protocol NSObject

- (BOOL)isEqual:(id)object;                     // 判断两个对象是否相等
- (NSUInteger)hash;

- (Class)superclass;                            // 返回对象的父类
- (Class)class;                                 // 返回对象的类型
- (id)self;
- (struct _NSZone *)zone OBJC_ARC_UNAVAILABLE;

- (id)performSelector:(SEL)aSelector;           // 向对象发送aSelector消息
- (id)performSelector:(SEL)aSelector withObject:(id)object; // 向对象发送aSelector消息，并带有该消息需要的一个参数
// 向对象发送aSelector消息，并带有该消息需要的两个参数
- (id)performSelector:(SEL)aSelector withObject:(id)object1 withObject:(id)object2;

- (BOOL)isProxy;                                // 判断是否是代理

- (BOOL)isKindOfClass:(Class)aClass;            // 是否是某个类（包括子类）
- (BOOL)isMemberOfClass:(Class)aClass;          // 是否是某个类（不包括子类）

- (BOOL)conformsToProtocol:(Protocol *)aProtocol;   // 判断是否遵守aProtocol协议
- (BOOL)respondsToSelector:(SEL)aSelector;          // 判断是否实现了aSelector方法

#pragma - mark MRC
- (id)retain OBJC_ARC_UNAVAILABLE;
- (oneway void)release OBJC_ARC_UNAVAILABLE;
- (id)autorelease OBJC_ARC_UNAVAILABLE;
- (NSUInteger)retainCount OBJC_ARC_UNAVAILABLE;

- (NSString *)description;

@optional
- (NSString *)debugDescription;

@end


__OSX_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0)
OBJC_ROOT_CLASS
OBJC_EXPORT
@interface NSObject <NSObject> {
    Class isa  OBJC_ISA_AVAILABILITY;
}

+ (void)load;

+ (void)initialize;     // 初始化， 类加载的时候执行，只执行一次
- (id)init;             // 初始化

+ (id)new;
+ (id)allocWithZone:(struct _NSZone *)zone;
+ (id)alloc;
- (void)dealloc;

- (void)finalize;

- (id)copy;
- (id)mutableCopy;

+ (id)copyWithZone:(struct _NSZone *)zone OBJC_ARC_UNAVAILABLE;
+ (id)mutableCopyWithZone:(struct _NSZone *)zone OBJC_ARC_UNAVAILABLE;

+ (Class)superclass;                                    // 返回父类类型
+ (Class)class;                                         // 返回类型
+ (BOOL)instancesRespondToSelector:(SEL)aSelector;      // 实例对象是否实现方法
+ (BOOL)conformsToProtocol:(Protocol *)protocol;        // 是否遵守协议

- (IMP)methodForSelector:(SEL)aSelector;                // 返回一个从aSelector创建的方法的实现
+ (IMP)instanceMethodForSelector:(SEL)aSelector;

- (void)doesNotRecognizeSelector:(SEL)aSelector;

- (id)forwardingTargetForSelector:(SEL)aSelector __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
- (void)forwardInvocation:(NSInvocation *)anInvocation;
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector;

+ (NSMethodSignature *)instanceMethodSignatureForSelector:(SEL)aSelector;

- (BOOL)allowsWeakReference UNAVAILABLE_ATTRIBUTE;
- (BOOL)retainWeakReference UNAVAILABLE_ATTRIBUTE;

+ (NSString *)description;

+ (BOOL)isSubclassOfClass:(Class)aClass;  // 是否是某个类的子类

+ (BOOL)resolveClassMethod:(SEL)sel __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
+ (BOOL)resolveInstanceMethod:(SEL)sel __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);

@end