Equality Operators

The following equality operator features are unsupported.

• Defining a pointer to member function type. Example:
  Listing: Example - Defining a Pointer to Member Function Type

  
  
  struct X {
        void f() {}
  
  };   
  
  typedef void (X::*PROC)();
  

• Permitting an implementation to compare a pointer to member operand with a constant expression which evaluates to zero using the == operator.
  Listing: Example - Permitting an Implemetation

  
  
  class X {
  public:
  
        int m;
  
  };   
  
  (void) ( &X::m == 0 );      
  
   -----------^-------------ERROR