/// When signing using a fallible method either an user-supplied `SignError` or a `CreationError`
/// may occur.
-///
-/// (C-not exported) As we don't support unbounded generics
#[derive(Eq, PartialEq, Debug, Clone)]
-pub enum SignOrCreationError<S> {
+pub enum SignOrCreationError<S = ()> {
/// An error occurred during signing
SignError(S),