thiserror 1.0.29 on Rust Cargo

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;