Newbie question about const

Newbie question about const

• David Vertex Harris

  Hi Brian,
  
  Thanks. This is a good one.
  For reference of others, more information can be obtained here
  
  http://msdn2.microsoft.com/en-us/library/4h2h0ktk(VS.80,d=ide).aspx
  
  
  
  

• eebrown

  Thanks a lot for such a quick response.
  
  What exactly do you mean when you say
  
  "won't change an instance of the class"
  
  Is there a function that could change instance of the class If so, how could it be done
  
  
  
  

• nathan.wells

  An exception to the rule is when a member is declared as mutable.  Data members marked as mutable can be modified by a const method.
  

• Krishnareddym

  See http://msdn.microsoft.com/library/default.asp url=/library/en-us/vccelng/htm/tions_25.asp

  
  
  

• Brian Teutsch

  Change the internal state of the object, like changing the value of one of its member variables.
  
  
  
  

• mattpdk

  It tells the compiler that the GetPlatformID() method won't change an instance of the class. That is important if you ever want to call this method on an object that is const. Simple example:
  
  class demo {
  public:
  void method1() const;
  void method2();
  };
  void testconst(const demo& obj) {
  obj.method1();
  obj.method2(); // Error C2662
  }
  
  
  
  

• Fran M.

  Thanks a lot !
  
  I get it now.
  
  
  
  

• Chandrashekhar K

  Hi Brian,
  
  Thanks. This is a good one.
  
  
  
  
  
• Newbie question about const