+/// A function for signing an [`UnsignedBolt12Invoice`].
+pub trait SignBolt12InvoiceFn {
+ /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
+ fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()>;
+}
+
+impl<F> SignBolt12InvoiceFn for F
+where
+ F: Fn(&UnsignedBolt12Invoice) -> Result<Signature, ()>,
+{
+ fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
+ self(message)
+ }
+}
+
+impl<F> SignFn<UnsignedBolt12Invoice> for F
+where
+ F: SignBolt12InvoiceFn,
+{
+ fn sign(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
+ self.sign_invoice(message)
+ }
+}
+