CODEWITHSUNDEEP
objective-c
gossamer
gossamer

Reputation: 93

passing object pointer as protocol pointer

@protocol protoA <NSObject>
@end

@interface objA : NSObject<protoA> {
    @private
    }
@end

@implementation objA
@end

@protocol protoB <NSObject>
    -(void) foo: (id <protoA> *) par;
@end

@interface objB : NSObject<protoB> 
    -(void) foo: (id <protoA> *) par;
@end

@implementation objB
    -(void) foo: (id <protoA> *) par
    {
    //...
    }
@end

in some other class method i use it this way:

objB *obj1 = [[objB alloc] init];
objA *obj2 = [[objA alloc] init];

[obj1 foo: obj2];

I have compiler error: "Implicit conversion of an Objective-C pointer to '__autoreleasing id*' is disallowed with ARC

What is the proper way to do get this functionality ?

Upvotes: 9

Views: 3734

Answers (3)

justin
justin

Reputation: 104708

If you want to specify type and protocol, you can use this form:

- (void)method:(MONType<MONProtocol>*)param;

If you want an opaque objc type (id) and protocol, use this form:

- (void)method:(id<MONProtocol>)param;

Upvotes: 2

hamstergene
hamstergene

Reputation: 24439

id is a pointer already, drop *:

-(void) foo: (id <protoA>) par

Upvotes: 4

Georg Fritzsche
Georg Fritzsche

Reputation: 99092

id already is a pointer-type, use just id<Protocol> instead of id<Protocol>*.

Upvotes: 15

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