(a) A spendthrift provision contained in a trust instrument is valid if it contains language substantially to the effect that it restrains both voluntary and involuntary transfers of a beneficiary's interest.
(b) A term of a trust instrument providing that the interest of a beneficiary is held subject to a "spendthrift trust," or words of similar import, is sufficient to restrain both voluntary and involuntary transfer of the beneficiary's interest.
(c) A beneficiary may not transfer an interest in a trust in violation of a valid spendthrift provision, and, except as otherwise provided in this article, a creditor or assignee of the beneficiary may not reach the interest or a distribution by the trustee before its receipt by the beneficiary.