1.0.29

• Support error types containing generic type parameters (#148, #149, #150, #151)

  use thiserror::Error;
  
  #[derive(Error, Debug)]
  pub enum MyError<E, F, G> {
      #[error("thing {0} ({0:?})")]
      Variant(E),
      #[error("some error")]
      Delegate(#[source] SomeError<F>),
      #[error("err 0o{val:o}")]
      Octal { val: G },
  }

  In the above example, thiserror would automatically generate the following pair of generic trait impls.

  impl<E, F, G> std::error::Error for MyError<E, F, G>
  where
      SomeError<F>: std::error::Error + 'static,
      Self: std::fmt::Debug + std::fmt::Display;
  
  impl<E, F, G> std::fmt::Display for MyError<E, F, G>
  where
      E: std::fmt::Debug + std::fmt::Display,
      G: std::fmt::Octal;