message: type-safer offset ctor
diff: @@ -11,15 +11,14 @@ pub enum Offset<T> {
  Uri(IdBuf<T>),
  }
  -impl<T> Offset<T> {
  +impl Offset<idtypes::Track> {
  pub fn for_position(position: u64) -> Offset<idtypes::Track> {
  Offset::Position(Duration::from_millis(position))
  }
  +}
  - pub fn for_uri(uri: &Id<T>) -> Offset<T>
  - where
  - T: PlayableIdType,
  - {
  +impl<T: PlayableTypeId> Offset<T> {
  + pub fn for_uri(uri: &Id<T>) -> Offset<T> {
  Offset::Uri(uri.to_owned())
  }
  }
  