# Heap::Elem::Ref - Object Reference Heap Elements - perldoc - [phpMan]

## NAME
    [Heap::Elem::Ref](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem%3A%3ARef/markdown) - Object Reference Heap Elements

## SYNOPSIS
      use [Heap::Elem::Ref](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem%3A%3ARef/markdown)( RefElem );
      use [Heap::Fibonacci](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AFibonacci/markdown);

      my $heap = [Heap::Fibonacci](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AFibonacci/markdown)->new;
      my $elem;

      foreach $i ( 1..100 ) {
          $obj = myObject->new( $i );
          $elem = RefElem( $obj );
          $heap->add( $elem );
      }

      while( defined( $elem = $heap->extract_top ) ) {
          # assume that myObject object have a method I<printable>
          print "Smallest is ", $elem->val->printable, "\n";
      }

## DESCRIPTION
    [Heap::Elem::Ref](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem%3A%3ARef/markdown) is used to wrap object reference values into an element that can be managed on a
    heap. Each referenced object must have a method *cmp* which can compare itself with any of the
    other objects that have references on the same heap. These comparisons must be consistant with
    normal arithmetic. The top of the heap will have the smallest (according to *cmp*) element still
    remaining. (See [Heap::Elem::RefRev](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem%3A%3ARefRev/markdown) if you want the heap to always return the largest element.)

    The details of the Elem interface are described in [Heap::Elem](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem/markdown).

    The details of using a Heap interface are described in Heap.

## AUTHOR
    John Macdonald, <john@perlwolf.com>

## COPYRIGHT
    Copyright 1998-2007, O'Reilly & Associates.

    This code is distributed under the same copyright terms as perl itself.

## SEE ALSO
    [Heap(3)](https://www.chedong.com/phpMan.php/man/Heap/3/markdown), Heap::[Elem(3)](https://www.chedong.com/phpMan.php/man/Elem/3/markdown), [Heap::Elem](https://www.chedong.com/phpMan.php/perldoc/Heap%3A%3AElem/markdown)::[RefRev(3)](https://www.chedong.com/phpMan.php/man/RefRev/3/markdown).