Add desmart/support to composer.json:

{
  "require": {
    "desmart/support": "1.0.*"
  }
}

Converts string to boolean values using filter_var() with FILTER_VALIDATE_BOOLEAN.
When filter_var() is unable to convert it to boolean exception will be thrown.

Example usage:

<?php
bool('1'); // true
bool('yes'); // true
bool('no'); // false
?>