为什么这个正则表达式会失败?

array(
    'rule1' => array(
        '/^.*[\d].*$/i',
        'Password must contain at least one number.'
    ),
    'rule2' => array(
        '/^.*[a-z].*$/i',
        'Password must contain at least one lowercase letter'
    ),
    'rule3' => array(
        '/^.*[A-Z].*$/i',
        'Password must contain at least one uppercase letter'
    ),
    'rule4' => array(
        '/^.*[~!@#$%^&*()_+=].*$/i',
        'Password must contain at least one special character [~!@#$%^&*()_+=]'
    )
);

出于某种原因,无论我通过了什么验证,“特殊字符”规则都会失败。我猜这是表达式的问题。如果有更好(或正确)的方法来写这些表达式,我洗耳恭听!