__toString()でExceptionが発生すると死ぬ ref: http://qiita.com/items/195222c4f4f223e435fa

file0.php

<?php
class Hoge {
  function __toString() {
    throw new Exception;
  }
}

try {
  $hoge = new Hoge;
  echo $hoge;
} catch (Exception $e) {
}