+/// This enum is used to specify which error data to send to peers when failing back an HTLC
+/// using [`ChannelManager::fail_htlc_backwards_with_reason`].
+///
+/// For more info on failure codes, see <https://github.com/lightning/bolts/blob/master/04-onion-routing.md#failure-messages>.
+#[derive(Clone, Copy)]
+pub enum FailureCode {
+ /// We had a temporary error processing the payment. Useful if no other error codes fit
+ /// and you want to indicate that the payer may want to retry.
+ TemporaryNodeFailure = 0x2000 | 2,
+ /// We have a required feature which was not in this onion. For example, you may require
+ /// some additional metadata that was not provided with this payment.
+ RequiredNodeFeatureMissing = 0x4000 | 0x2000 | 3,
+ /// You may wish to use this when a `payment_preimage` is unknown, or the CLTV expiry of
+ /// the HTLC is too close to the current block height for safe handling.
+ /// Using this failure code in [`ChannelManager::fail_htlc_backwards_with_reason`] is
+ /// equivalent to calling [`ChannelManager::fail_htlc_backwards`].
+ IncorrectOrUnknownPaymentDetails = 0x4000 | 15,
+}
+