c++ - const correctness and member pointers -

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i have const on accelerate method, yet can call power method. way stop this.

class engine{ public:     void power(){     } };  class car{ public:     car() : p(new engine()){}      void accelerator() const{         p->power();     }      private:         engine* p; };

for car, const method methods not modify car member variables.

so, long car::accelerator not make p point different location, valid.

since p not modified in accelerator (meaning not point different memory address), program valid.

the moment make p point different location, program fails compile:

  void accelerator() const {         p= nullptr; //wrong   }

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