Memory management for "id<ProtocolName> variableName" type properties

I'm having a problem with properties of the following type:

id<ProtocolName> variableName;
.....
.....
@property (nonatomic, retain) id<ProtocolName> variableName;

I can access and use them just fine, but when I try to call

[variableName release];

I get compiler warnings:

'-release' not found in protocol(s)

Do I need to define a release method in the interf开发者_StackOverflow社区ace, or how do I release the memory reserved for the variable?

Thanks!

---

Make your protocol adopts NSObject.

@protocol ProtocolName <NSObject>
...

---

release is in the NSObject protocol, so you can declare it as id<ProtocolName, NSObject> to work within the type system or cast it to a plain id to stop its class from being typechecked.

---

You can always add NSObject to the protocol list.