Project OpenGeode ​

class PassKey ​

This can be used to restrict which class can call methods Example: class A { // Add a key only B can create PASSKEY( B, KeyForB );

 public:         void restrictive_method( KeyForB )         {             // do something         }     };

 Now, B class is the only class that can call A::restrictive_method     class B     {     public:          void run( A& a )          {              // the {} will implicitly create a KeyForB              a.restrictive_method( {} );          }     };