weakmap.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<phpdoc:classref xml:id="class.weakmap" xmlns:phpdoc="http://php.net/ns/phpdoc" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xi="http://www.w3.org/2001/XInclude">

 <title>The WeakMap class</title>
 <titleabbrev>WeakMap</titleabbrev>

 <partintro>

  <!-- {{{ WeakMap intro -->
  <section xml:id="weakmap.intro">
   &reftitle.intro;
   <para>
    A <classname>WeakMap</classname> is map (or dictionary) that accepts objects as keys.  However, unlike the
    otherwise similar <classname>SplObjectStorage</classname>, an object in a key of <classname>WeakMap</classname>
    does not contribute toward the object's reference count.  That is, if at any point the only remaining reference
    to an object is the key of a <classname>WeakMap</classname>, the object will be garbage collected and removed
    from the <classname>WeakMap</classname>.  Its primary use case is for building caches of data derived from
    an object that do not need to live longer than the object.
   </para>
   <para>
    <classname>WeakMap</classname> implements <interfacename>ArrayAccess</interfacename>,
    <interfacename>Iterator</interfacename>, and <interfacename>Countable</interfacename>,
    so in most cases it can be used in the same fashion as an associative array.
   </para>
  </section>
  <!-- }}} -->

  <section xml:id="weakmap.synopsis">
   &reftitle.classsynopsis;

   <!-- {{{ Synopsis -->
   <classsynopsis class="class">
    <ooclass>
     <modifier>final</modifier>
     <classname>WeakMap</classname>
    </ooclass>

    <oointerface>
     <modifier>implements</modifier>
     <interfacename>ArrayAccess</interfacename>
    </oointerface>

    <oointerface>
     <interfacename>Countable</interfacename>
    </oointerface>

    <oointerface>
     <interfacename>IteratorAggregate</interfacename>
    </oointerface>

    <classsynopsisinfo role="comment">&Methods;</classsynopsisinfo>
    <xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.weakmap')/db:refentry/db:refsect1[@role='description']/descendant::db:methodsynopsis[@role='WeakMap'])">
     <xi:fallback/>
    </xi:include>
   </classsynopsis>
   <!-- }}} -->

  </section>
  <!-- {{{ weakmap examples -->
  <section xml:id="weakmap.examples">
   &reftitle.examples;
   <para>
    <example>
     <title><classname>Weakmap</classname> usage example</title>
     <programlisting role="php">
      <![CDATA[
<?php
$wm = new WeakMap();

$o = new stdClass;

class A {
    public function __destruct() {
        echo "Dead!\n";
    }
}

$wm[$o] = new A;

var_dump(count($wm));
echo "Unsetting...\n";
unset($o);
echo "Done\n";
var_dump(count($wm));
]]>
     </programlisting>
     &example.outputs;
     <screen>
      <![CDATA[
int(1)
Unsetting...
Dead!
Done
int(0)
]]>
     </screen>
    </example>
   </para>
  </section>
  <!-- }}} -->

 </partintro>

 &language.predefined.weakmap.count;
 &language.predefined.weakmap.getiterator;
 &language.predefined.weakmap.offsetexists;
 &language.predefined.weakmap.offsetget;
 &language.predefined.weakmap.offsetset;
 &language.predefined.weakmap.offsetunset;

</phpdoc:classref>
<!-- Keep this comment at the end of the file
 Local variables:
 mode: sgml
 sgml-omittag:t
 sgml-shorttag:t
 sgml-minimize-attributes:nil
 sgml-always-quote-attributes:t
 sgml-indent-step:1
 sgml-indent-data:t
 indent-tabs-mode:nil
 sgml-parent-document:nil
 sgml-default-dtd-file:"~/.phpdoc/manual.ced"
 sgml-exposed-tags:nil
 sgml-local-catalogs:nil
 sgml-local-ecat-files:nil
 End:
 vim600: syn=xml fen fdm=syntax fdl=2 si
 vim: et tw=78 syn=sgml
 vi: ts=1 sw=1
 -->