| // RUN: %clang_cc1 -fblocks -fsyntax-only %s -verify -Wmethod-signatures | 
 |  | 
 | // Tests Objective-C 'kindof' types. | 
 |  | 
 | #if !__has_feature(objc_kindof) | 
 | #error does not support __kindof | 
 | #endif | 
 |  | 
 | @protocol NSObject | 
 | @end | 
 |  | 
 | @protocol NSCopying | 
 | - (id)copy; | 
 | + (Class)classCopy; | 
 | @end | 
 |  | 
 | @protocol NSRandomProto | 
 | - (void)randomMethod; | 
 | + (void)randomClassMethod; | 
 | @end | 
 |  | 
 | __attribute__((objc_root_class)) | 
 | @interface NSObject <NSObject> | 
 | - (NSObject *)retain; | 
 | @end | 
 |  | 
 | @interface NSString : NSObject <NSCopying> // expected-note{{receiver is instance of class declared here}} | 
 | - (void)compare:(NSString *)string; | 
 | - (NSString *)stringByAppendingString:(NSString *)string; | 
 | + (instancetype)string; | 
 | @end | 
 |  | 
 | @interface NSMutableString : NSString | 
 | - (void)appendString:(NSString *)string; | 
 | @end | 
 |  | 
 | @interface NSNumber : NSObject <NSCopying> | 
 | - (NSNumber *)numberByAddingNumber:(NSNumber *)number; | 
 | @end | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Parsing and semantic analysis for __kindof | 
 | // --------------------------------------------------------------------------- | 
 |  | 
 | // Test proper application of __kindof. | 
 | typedef __kindof NSObject *typedef1; | 
 | typedef NSObject __kindof *typedef2; | 
 | typedef __kindof NSObject<NSCopying> typedef3; | 
 | typedef NSObject<NSCopying> __kindof *typedef4; | 
 | typedef __kindof id<NSCopying> typedef5; | 
 | typedef __kindof Class<NSCopying> typedef6; | 
 |  | 
 | // Test redundancy of __kindof. | 
 | typedef __kindof id __kindof redundant_typedef1; | 
 | typedef __kindof NSObject __kindof *redundant_typedef2; | 
 |  | 
 | // Test application of __kindof to typedefs. | 
 | typedef NSObject *NSObject_ptr_typedef; | 
 | typedef NSObject NSObject_typedef; | 
 | typedef __kindof NSObject_ptr_typedef typedef_typedef1; | 
 | typedef __kindof NSObject_typedef typedef_typedef2; | 
 |  | 
 | // Test application of __kindof to non-object types. | 
 | typedef __kindof int nonobject_typedef1; // expected-error{{'__kindof' specifier cannot be applied to non-object type 'int'}} | 
 | typedef NSObject **NSObject_ptr_ptr; | 
 | typedef __kindof NSObject_ptr_ptr nonobject_typedef2; // expected-error{{'__kindof' specifier cannot be applied to non-object type 'NSObject_ptr_ptr' (aka 'NSObject **')}} | 
 |  | 
 | // Test application of __kindof outside of the decl-specifiers. | 
 | typedef NSObject * __kindof bad_specifier_location1; // expected-error{{'__kindof' type specifier must precede the declarator}} | 
 | typedef NSObject bad_specifier_location2 __kindof; // expected-error{{expected ';' after top level declarator}} | 
 | // expected-warning@-1{{declaration does not declare anything}} | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Pretty printing of __kindof | 
 | // --------------------------------------------------------------------------- | 
 | void test_pretty_print(int *ip) { | 
 |   __kindof NSObject *kindof_NSObject; | 
 |   ip = kindof_NSObject; // expected-warning{{from '__kindof NSObject *'}} | 
 |   | 
 |   __kindof NSObject_ptr_typedef kindof_NSObject_ptr; | 
 |   ip = kindof_NSObject_ptr; // expected-warning{{from '__kindof NSObject_ptr_typedef'}} | 
 |  | 
 |   __kindof id <NSCopying> *kindof_NSCopying; | 
 |   ip = kindof_NSCopying; // expected-warning{{from '__kindof id<NSCopying> *'}} | 
 |  | 
 |   __kindof NSObject_ptr_typedef *kindof_NSObject_ptr_typedef; | 
 |   ip = kindof_NSObject_ptr_typedef; // expected-warning{{from '__kindof NSObject_ptr_typedef *'}} | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Basic implicit conversions (dropping __kindof, upcasts, etc.) | 
 | // --------------------------------------------------------------------------- | 
 | void test_add_remove_kindof_conversions(void) { | 
 |   __kindof NSObject *kindof_NSObject_obj; | 
 |   NSObject *NSObject_obj; | 
 |  | 
 |   // Conversion back and forth | 
 |   kindof_NSObject_obj = NSObject_obj; | 
 |   NSObject_obj = kindof_NSObject_obj; | 
 |  | 
 |   // Qualified-id conversion back and forth. | 
 |   __kindof id <NSCopying> kindof_id_NSCopying_obj; | 
 |   id <NSCopying> id_NSCopying_obj; | 
 |   kindof_id_NSCopying_obj = id_NSCopying_obj; | 
 |   id_NSCopying_obj = kindof_id_NSCopying_obj; | 
 | } | 
 |  | 
 | void test_upcast_conversions(void) { | 
 |   __kindof NSObject *kindof_NSObject_obj; | 
 |   NSObject *NSObject_obj; | 
 |  | 
 |   // Upcasts | 
 |   __kindof NSString *kindof_NSString_obj; | 
 |   NSString *NSString_obj; | 
 |   kindof_NSObject_obj = kindof_NSString_obj; | 
 |   kindof_NSObject_obj = NSString_obj; | 
 |   NSObject_obj = kindof_NSString_obj; | 
 |   NSObject_obj = NSString_obj; | 
 |  | 
 |   // "Upcasts" with qualified-id. | 
 |   __kindof id <NSCopying> kindof_id_NSCopying_obj; | 
 |   id <NSCopying> id_NSCopying_obj; | 
 |   kindof_id_NSCopying_obj = kindof_NSString_obj; | 
 |   kindof_id_NSCopying_obj = NSString_obj; | 
 |   id_NSCopying_obj = kindof_NSString_obj; | 
 |   id_NSCopying_obj = NSString_obj; | 
 | } | 
 |  | 
 |  | 
 | void test_ptr_object_conversions(void) { | 
 |   __kindof NSObject **ptr_kindof_NSObject_obj; | 
 |   NSObject **ptr_NSObject_obj; | 
 |  | 
 |   // Conversions back and forth. | 
 |   ptr_kindof_NSObject_obj = ptr_NSObject_obj; | 
 |   ptr_NSObject_obj = ptr_kindof_NSObject_obj; | 
 |  | 
 |   // Conversions back and forth with qualified-id. | 
 |   __kindof id <NSCopying> *ptr_kindof_id_NSCopying_obj; | 
 |   id <NSCopying> *ptr_id_NSCopying_obj; | 
 |   ptr_kindof_id_NSCopying_obj = ptr_id_NSCopying_obj; | 
 |   ptr_id_NSCopying_obj = ptr_kindof_id_NSCopying_obj; | 
 |  | 
 |   // Upcasts. | 
 |   __kindof NSString **ptr_kindof_NSString_obj; | 
 |   NSString **ptr_NSString_obj; | 
 |   ptr_kindof_NSObject_obj = ptr_kindof_NSString_obj; | 
 |   ptr_kindof_NSObject_obj = ptr_NSString_obj; | 
 |   ptr_NSObject_obj = ptr_kindof_NSString_obj; | 
 |   ptr_NSObject_obj = ptr_NSString_obj; | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Implicit downcasting | 
 | // --------------------------------------------------------------------------- | 
 | void test_downcast_conversions(void) { | 
 |   __kindof NSObject *kindof_NSObject_obj; | 
 |   NSObject *NSObject_obj; | 
 |   __kindof NSString *kindof_NSString_obj; | 
 |   NSString *NSString_obj; | 
 |  | 
 |   // Implicit downcasting. | 
 |   kindof_NSString_obj = kindof_NSObject_obj; | 
 |   kindof_NSString_obj = NSObject_obj; // expected-warning{{assigning to '__kindof NSString *' from 'NSObject *'}} | 
 |   NSString_obj = kindof_NSObject_obj; | 
 |   NSString_obj = NSObject_obj; // expected-warning{{assigning to 'NSString *' from 'NSObject *'}} | 
 |  | 
 |   // Implicit downcasting with qualified id. | 
 |   __kindof id <NSCopying> kindof_NSCopying_obj; | 
 |   id <NSCopying> NSCopying_obj; | 
 |   kindof_NSString_obj = kindof_NSCopying_obj; | 
 |   kindof_NSString_obj = NSCopying_obj; // expected-warning{{from incompatible type 'id<NSCopying>'}} | 
 |   NSString_obj = kindof_NSCopying_obj; | 
 |   NSString_obj = NSCopying_obj; // expected-warning{{from incompatible type 'id<NSCopying>'}} | 
 |   kindof_NSObject_obj = kindof_NSCopying_obj; | 
 |   kindof_NSObject_obj = NSCopying_obj; // expected-warning{{from incompatible type 'id<NSCopying>'}} | 
 |   NSObject_obj = kindof_NSCopying_obj; | 
 |   NSObject_obj = NSCopying_obj; // expected-warning{{from incompatible type 'id<NSCopying>'}} | 
 | } | 
 |  | 
 | void test_crosscast_conversions(void) { | 
 |   __kindof NSString *kindof_NSString_obj; | 
 |   NSString *NSString_obj; | 
 |   __kindof NSNumber *kindof_NSNumber_obj; | 
 |   NSNumber *NSNumber_obj; | 
 |  | 
 |   NSString_obj = kindof_NSNumber_obj; // expected-warning{{from '__kindof NSNumber *'}} | 
 | } | 
 |  | 
 | @interface NSCell : NSObject | 
 | @end | 
 | @interface NSCellSub : NSCell | 
 | @end | 
 | @interface NSCellSub2 : NSCell | 
 | @end | 
 | @interface NSCellSubSub : NSCellSub | 
 | @end | 
 |  | 
 | typedef signed char BOOL; | 
 | void test_conditional(BOOL flag) { | 
 |   NSCellSubSub *result; | 
 |   __kindof NSCellSub *kindof_Sub; | 
 |   NSCell *cell; | 
 |   NSCellSub *sub; | 
 |   NSCellSub2 *sub2; | 
 |   NSCellSubSub *subsub; | 
 |  | 
 |   // LHS is kindof NSCellSub, RHS is NSCell --> kindof NSCell | 
 |   // LHS is kindof NSCellSub, RHS is NSCellSub --> kindof NSCellSub | 
 |   // LHS is kindof NSCellSub, RHS is NSCellSub2 --> kindof NSCell | 
 |   // LHS is kindof NSCellSub, RHS is NSCellSubSub --> kindof NSCellSub | 
 |   result = flag ? kindof_Sub : cell; | 
 |   result = flag ? kindof_Sub : sub; | 
 |   result = flag ? kindof_Sub : sub2; | 
 |   result = flag ? kindof_Sub : subsub; | 
 |  | 
 |   result = flag ? cell : kindof_Sub; | 
 |   result = flag ? sub : kindof_Sub; | 
 |   result = flag ? sub2 : kindof_Sub; | 
 |   result = flag ? subsub : kindof_Sub; | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Blocks | 
 | // --------------------------------------------------------------------------- | 
 | void test_block_conversions(void) { | 
 |   // Adding/removing __kindof from return type. | 
 |   __kindof NSString *(^kindof_NSString_void_block)(void); | 
 |   NSString *(^NSString_void_block)(void); | 
 |   kindof_NSString_void_block = NSString_void_block; | 
 |   NSString_void_block = kindof_NSString_void_block; | 
 |  | 
 |   // Covariant return type. | 
 |   __kindof NSMutableString *(^kindof_NSMutableString_void_block)(void); | 
 |   NSMutableString *(^NSMutableString_void_block)(void); | 
 |   kindof_NSString_void_block = NSMutableString_void_block; | 
 |   NSString_void_block = kindof_NSMutableString_void_block; | 
 |   kindof_NSString_void_block = NSMutableString_void_block; | 
 |   NSString_void_block = kindof_NSMutableString_void_block; | 
 |  | 
 |   // "Covariant" return type via downcasting rule. | 
 |   kindof_NSMutableString_void_block = NSString_void_block; // expected-error{{from 'NSString *(^)(void)'}} | 
 |   NSMutableString_void_block = kindof_NSString_void_block; | 
 |   kindof_NSMutableString_void_block = NSString_void_block; // expected-error{{from 'NSString *(^)(void)'}} | 
 |   NSMutableString_void_block = kindof_NSString_void_block; | 
 |  | 
 |   // Cross-casted return type. | 
 |   __kindof NSNumber *(^kindof_NSNumber_void_block)(void); | 
 |   NSNumber *(^NSNumber_void_block)(void); | 
 |   kindof_NSString_void_block = NSNumber_void_block; // expected-error{{from 'NSNumber *(^)(void)'}} | 
 |   NSString_void_block = kindof_NSNumber_void_block; // expected-error{{'__kindof NSNumber *(^)(void)'}} | 
 |   kindof_NSString_void_block = NSNumber_void_block; // expected-error{{from 'NSNumber *(^)(void)'}} | 
 |   NSString_void_block = kindof_NSNumber_void_block; // expected-error{{'__kindof NSNumber *(^)(void)'}} | 
 |  | 
 |   // Adding/removing __kindof from argument type. | 
 |   void (^void_kindof_NSString_block)(__kindof NSString *); | 
 |   void (^void_NSString_block)(NSString *); | 
 |   void_kindof_NSString_block = void_NSString_block; | 
 |   void_NSString_block = void_kindof_NSString_block; | 
 |  | 
 |   // Contravariant argument type. | 
 |   void (^void_kindof_NSMutableString_block)(__kindof NSMutableString *); | 
 |   void (^void_NSMutableString_block)(NSMutableString *); | 
 |   void_kindof_NSMutableString_block = void_kindof_NSString_block; | 
 |   void_kindof_NSMutableString_block = void_NSString_block; | 
 |   void_NSMutableString_block = void_kindof_NSString_block; | 
 |   void_NSMutableString_block = void_NSString_block; | 
 |  | 
 |   // "Contravariant" argument type via downcasting rule. | 
 |   void_kindof_NSString_block = void_kindof_NSMutableString_block; | 
 |   void_kindof_NSString_block = void_NSMutableString_block; | 
 |   void_NSString_block = void_kindof_NSMutableString_block; // expected-error{{from 'void (^)(__kindof NSMutableString *)'}} | 
 |   void_NSString_block = void_NSMutableString_block; // expected-error{{from 'void (^)(NSMutableString *)'}} | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // Messaging __kindof types. | 
 | // --------------------------------------------------------------------------- | 
 | void message_kindof_object(__kindof NSString *kindof_NSString) { | 
 |   [kindof_NSString retain]; // in superclass | 
 |   [kindof_NSString stringByAppendingString:0]; // in class | 
 |   [kindof_NSString appendString:0]; // in subclass | 
 |   [kindof_NSString numberByAddingNumber: 0]; // expected-warning{{instance method '-numberByAddingNumber:' not found (return type defaults to 'id')}} | 
 |   [kindof_NSString randomMethod]; // in protocol | 
 | } | 
 |  | 
 | void message_kindof_qualified_id(__kindof id <NSCopying> kindof_NSCopying) { | 
 |   [kindof_NSCopying copy]; // in protocol | 
 |   [kindof_NSCopying stringByAppendingString:0]; // in some class | 
 |   [kindof_NSCopying randomMethod]; // in unrelated protocol | 
 | } | 
 |  | 
 | void message_kindof_qualified_class( | 
 |        __kindof Class <NSCopying> kindof_NSCopying) { | 
 |   [kindof_NSCopying classCopy]; // in protocol | 
 |   [kindof_NSCopying string]; // in some class | 
 |   [kindof_NSCopying randomClassMethod]; // in unrelated protocol | 
 | } | 
 |  | 
 | // Make sure we don't emit warning about multiple methods found. | 
 | typedef int NSInteger; | 
 | @interface Foo : NSObject | 
 | - (NSString*)test; | 
 | @end | 
 | @interface Bar : NSObject | 
 | - (NSInteger)test; | 
 | @end | 
 | void test(__kindof Bar *kBar) { | 
 |     [kBar test]; | 
 | } | 
 |  | 
 | // Make sure we don't emit warning about no method found. | 
 | @interface A : NSObject | 
 | @property (readonly, getter=isActive) BOOL active; | 
 | @end | 
 | @interface B : NSObject | 
 | @property (getter=isActive, readonly) BOOL active; | 
 | @end | 
 | void foo(void) { | 
 |   __kindof B *NSApp; | 
 |   if ([NSApp isActive]) { | 
 |   } | 
 | } | 
 |  | 
 | typedef const struct CGPath *CGPathRef; | 
 | @interface C : NSObject | 
 | @property (copy) NSString *path; | 
 | @end | 
 | @interface D : NSObject | 
 | @property CGPathRef path __attribute__((availability(macosx,unavailable))); | 
 | @end | 
 | // Make sure we choose "NSString *path" for [s1 path]. | 
 | void bar(id s1, id s2) { | 
 |   return [[s1 path] compare:[s2 path]]; | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // __kindof within specialized types | 
 | // --------------------------------------------------------------------------- | 
 | @interface NSArray<T> : NSObject | 
 | @end | 
 |  | 
 | void implicit_convert_array(NSArray<__kindof NSString *> *kindofStringsArray, | 
 |                             NSArray<NSString *> *stringsArray, | 
 |                             NSArray<__kindof NSMutableString *> | 
 |                               *kindofMutStringsArray, | 
 |                             NSArray<NSMutableString *> *mutStringsArray) { | 
 |   // Adding/removing __kindof is okay. | 
 |   kindofStringsArray = stringsArray; | 
 |   stringsArray = kindofStringsArray; | 
 |  | 
 |   // Other covariant and contravariant conversions still not permitted. | 
 |   kindofStringsArray = mutStringsArray; // expected-warning{{incompatible pointer types}} | 
 |   stringsArray = kindofMutStringsArray; // expected-warning{{incompatible pointer types}} | 
 |   mutStringsArray = kindofStringsArray; // expected-warning{{incompatible pointer types}} | 
 |  | 
 |   // Adding/removing nested __kindof is okay. | 
 |   NSArray<NSArray<__kindof NSString *> *> *kindofStringsArrayArray; | 
 |   NSArray<NSArray<NSString *> *> *stringsArrayArray; | 
 |   kindofStringsArrayArray = stringsArrayArray; | 
 |   stringsArrayArray = kindofStringsArrayArray; | 
 | } | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // __kindof + nullability | 
 | // --------------------------------------------------------------------------- | 
 |  | 
 | void testNullability(void) { | 
 |   // The base type being a pointer type tickles the bug. | 
 |   extern __kindof id <NSCopying> _Nonnull getSomeCopyable(void); | 
 |   NSString *string = getSomeCopyable(); // no-warning | 
 |  | 
 |   void processCopyable(__typeof(getSomeCopyable()) string); | 
 |   processCopyable(0); // expected-warning{{null passed to a callee that requires a non-null argument}} | 
 | } | 
 |  | 
 | // Make sure that we don't emit a warning about conflicting parameter types | 
 | // between __kindof id and id. | 
 | @interface A2 : NSObject | 
 | - (void)test:(__kindof id)T; | 
 | @end | 
 | @implementation A2 | 
 | - (void)test:(id)T { | 
 | } | 
 | @end | 
 |  | 
 | // --------------------------------------------------------------------------- | 
 | // __kindof on type parameters | 
 | // --------------------------------------------------------------------------- | 
 |  | 
 | @interface NSGeneric<ObjectType> : NSObject | 
 | - (void)test:(__kindof ObjectType)T; // expected-note{{passing argument to parameter 'T' here}} | 
 | - (void)mapUsingBlock:(id (^)(__kindof ObjectType))block; | 
 | @property (copy) ObjectType object; | 
 | @property (copy) __kindof ObjectType kindof_object; | 
 |  | 
 | @property (copy) __kindof ObjectType _Nonnull nonnull_kindof_object; | 
 | @end | 
 | @implementation NSGeneric | 
 | - (void)test:(id)T { | 
 | } | 
 | - (void)mapUsingBlock:(id (^)(id))block { | 
 | } | 
 | @end | 
 |  | 
 | @interface NSDefaultGeneric<ObjectType : NSString *> : NSObject | 
 | @property (copy) ObjectType object; | 
 | @property (copy) __kindof ObjectType kindof_object; | 
 | @end | 
 |  | 
 | void testGeneric(NSGeneric<NSString*> *generic) { | 
 |   NSObject *NSObject_obj; | 
 |   // Assign from NSObject_obj to __kindof NSString*. | 
 |   [generic test:NSObject_obj]; // expected-warning{{incompatible pointer types sending 'NSObject *' to parameter of type '__kindof NSString *'}} | 
 |   NSString *NSString_str; | 
 |   [generic test:NSString_str]; | 
 | } | 
 |  | 
 | void testGenericAssignment(void) { | 
 |   NSMutableString *NSMutableString_str; | 
 |   NSNumber *NSNumber_obj; | 
 |  | 
 |   NSGeneric<NSString*> *generic; | 
 |   NSMutableString_str = generic.object; // expected-warning{{incompatible pointer types}} | 
 |   NSNumber_obj = generic.object; // expected-warning{{incompatible pointer types}} | 
 |   NSMutableString_str = generic.kindof_object; | 
 |   NSNumber_obj = generic.kindof_object; // expected-warning{{incompatible pointer types assigning to 'NSNumber *' from '__kindof NSString *'}} | 
 |  | 
 |   NSGeneric<__kindof NSString*> *kindof_generic; | 
 |   NSMutableString_str = kindof_generic.object; | 
 |   NSNumber_obj = kindof_generic.object; // expected-warning{{incompatible pointer types assigning to 'NSNumber *' from '__kindof NSString *'}} | 
 |   NSMutableString_str = kindof_generic.kindof_object; | 
 |   NSNumber_obj = kindof_generic.kindof_object; // expected-warning{{incompatible pointer types assigning to 'NSNumber *' from '__kindof __kindof NSString *'}} | 
 |  | 
 |   NSDefaultGeneric *default_generic; | 
 |   NSMutableString_str = default_generic.object; | 
 |   NSNumber_obj = default_generic.object; // expected-warning{{incompatible pointer types}} | 
 |   NSMutableString_str = default_generic.kindof_object; | 
 |   NSNumber_obj = default_generic.kindof_object; // expected-warning{{incompatible pointer types assigning to 'NSNumber *' from '__kindof __kindof NSString *'}} | 
 |  | 
 |   typedef NSString *Typedef_NSString; | 
 |   NSGeneric<Typedef_NSString> *typedef_generic; | 
 |   NSMutableString_str = typedef_generic.object; // expected-warning{{incompatible pointer types}} | 
 |   NSNumber_obj = typedef_generic.object; // expected-warning{{incompatible pointer types}} | 
 |   NSMutableString_str = typedef_generic.kindof_object; | 
 |   NSNumber_obj = typedef_generic.kindof_object; // expected-warning{{incompatible pointer types assigning to 'NSNumber *' from '__kindof Typedef_NSString'}} | 
 | } | 
 |  | 
 | void testKindofNonObjectType(void) { | 
 |   typedef void (^BlockType)(int); | 
 |   NSGeneric<BlockType> *generic; | 
 | } | 
 |  | 
 | void testKindofNullability(NSGeneric<NSString*> *generic) { | 
 |   generic.nonnull_kindof_object = 0; // expected-warning{{null passed to a callee that requires a non-null argument}} | 
 | } | 
 |  | 
 | // Check that clang doesn't crash when a type parameter is illegal. | 
 | @interface Array1<T> : NSObject | 
 | @end | 
 |  | 
 | @interface I1 : NSObject | 
 | @end | 
 |  | 
 | @interface Array1<__kindof I1*>(extensions1) // expected-error{{expected type parameter name}} | 
 | @end | 
 |  | 
 | @interface Array2<T1, T2, T3> : NSObject | 
 | @end | 
 |  | 
 | @interface Array2<T, T, __kindof I1*>(extensions2) // expected-error{{expected type parameter name}} expected-error{{redeclaration of type parameter 'T'}} | 
 | @end |