Tests serializing a class with custom serialize functions

serialize_test.php

#!/usr/bin/php
<?php

class Test implements Serializable {

  public function __tostring() {
    return "asdf";
  }

  public function serialize() {
    return "qwerty";
  }

  public function unserialize($data) {
    echo $data;
  }

}

$test = new Test();
$a    = (string) $test;      // serialize via type-casting
$b    = $test->serialize();  // serialize via Serializable's serialize()
$c    = $test->__tostring(); // serialize via __tostring()
$d    = serialize($test);    // serialize via global php namespace's serialize()

echo "a = " . $a . "\n"; // print $a to stdout
echo "b = " . $b . "\n"; // print $b to stdout
echo "c = " . $c . "\n"; // print $c to stdout
echo "d = " . $d . "\n"; // print $d to stdout

// results on php-cli 5.5.27:
// a = asdf
// b = qwerty
// c = asdf
// d = C:4:"Test":6:{qwerty}