Implicit and explicit trusting.

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If you have any requirement where a class has to share some of its information (not all). With an external system, or we can say a condition where we have to violate encapsulation. Then we will use two different methods to activate it –
     

     1.       Implicit trusting –

Share your class’s private information with an object which is created by your class only. Or object which can be created by your class in the future. For example, iterator design pattern. In many cases, we destroy the object once the job is done. So the life cycle of the object is in your hand. That's why we call it implicit trusting. As you have some kind of control over it, and you are the owner of that object. Destroy it whenever you feel the work gets completed.

     2.       Explicit trusting –


Share class’s private information with trusted object. Here object is not created by your class. But you have the prior knowledge of object which is requesting your class to know it's internal state. It’s up to your class; to allow them or not. For example, visitor design pattern. Where you know the signature of requesting object. You can very well decline to share information about your class's internal state. If you see the object's signature is not proper. As your class is not open to all other classes. It will act like a black box, for others.
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