How can I differentiate the same method name of two protocols in a class implementation?

Question

I have two protocols

@protocol P1

-(void) printP1;

-(void) printCommon;

@end


@protocol P2

-(void) printP2;

-(void) printCommon;
@end

Now, I am implementing these two protocols in one class

@interface TestProtocolImplementation : NSObject <P1,P2>
{

}

@end

How can i write method implementation for "printCommon". When i try to do implementation i have compile time error.

Is there any possibility to write method implementation for "printCommon".

Answer 1

The common solution is to separate the common protocol and make the derived protocols implement the common protocol, like so:

@protocol PrintCommon

-(void) printCommon;

@end

@protocol P1 < PrintCommon > // << a protocol which declares adoption to a protocol

-(void) printP1;

// -(void) printCommon; << available via PrintCommon

@end


@protocol P2 < PrintCommon >

-(void) printP2;

@end

Now types which adopt P1 and P2 must also adopt PrintCommon's methods in order to fulfill adoption, and you may safely pass an NSObject<P1>* through NSObject<PrintCommon>* parameters.