CS 340 - 3/7/13

Pointers to Functions
 - Templating uses this idea


Template<class X>
void sort (X arr[], int size);  // uses operator<

// uses the function passed by the parameter
// for the comparison
Template<class X>
void sort (X arr[], int size, 
           bool (*comp)(const X&, const X&));

    

// The C++ STL uses something like the following
//  that uses the default parameter value of
//  the overloaded operator< as the default 
//  comparitor function/method
Template<class X>
void sort (X arr[], int size, 
           bool (*comp)(const X&, const X&) =
           bool X::operator< (const X&) );



class Point
{
...
};

class Student
{
// possible data values: grade, name, UIN, Univeristy
//  major, ...
...
};

bool compByName(const Student &s1, const Student &s2)
{
   return (strcmp (s1.getName(), s2getName() ) < 0);
}


bool compByUIN(const Student &s1, const Student &s2)
{
   return (s1.UIN().lessThan( s2.UIN() ) );
}


Student array1[1000];
...

   
   sort (array1, size, compByName );

   sort (array1, size, compByUIN );