title: the object has type qualifiers that are not compatible with the member function
body: <pre><code>#include&lt;iostream&gt;
  
  using namespace std;
  
  class PhoneNumber
  
  {
  
      int areacode;
      int localnum;
  public:
  
      PhoneNumber();
      PhoneNumber(const int, const int);
      void display() const;
      bool valid() const;
      void set(int, int);
      PhoneNumber&amp; operator=(const PhoneNumber&amp; no);
      PhoneNumber(const PhoneNumber&amp;);
  };
  
  istream&amp; operator&gt;&gt;(istream&amp; is, const PhoneNumber&amp; no);
  
  
  istream&amp; operator&gt;&gt;(istream&amp; is, const PhoneNumber&amp; no)
  {
  
      int area, local;
      cout &lt;&lt; "Area Code     : ";
      is &gt;&gt; area;
      cout &lt;&lt; "Local number  : ";
      is &gt;&gt; local;
      no.set(area, local);
      return is;
  }
  </code></pre>
  
  <p><strong>at no.set(area, local);</strong> it says that "the object has type qualifiers that are not compatible with the member function"</p>
  
  <p>what should i do...?</p>