Provide a default implementation

README.md

@@ -24,7 +24,3 @@ This crate does not attempt to be 100% compatible with the stabilization effort,
 ## Show me
 
 `cargo run --example simple`
-
-## Why not a derive macro?
-
-PRs welcome! :)

examples/simple.rs

@@ -1,4 +1,4 @@
-use error_iter::ErrorIter;
+use error_iter::ErrorIter as _;
 use std::io::{Error as IoError, ErrorKind};
 use thiserror::Error;
 
@@ -11,8 +11,6 @@ enum Error {
     _Unknown,
 }
 
-impl ErrorIter for Error {}
-
 fn main() {
     let error = Error::from(IoError::new(ErrorKind::Other, "oh no!"));
 

src/lib.rs

@@ -1,7 +1,7 @@
 //! Iterators over `std::error::Error` sources on stable Rust.
 //!
 //! ```
-//! use error_iter::ErrorIter;
+//! use error_iter::ErrorIter as _;
 //! use std::io::{Error as IoError, ErrorKind};
 //! use thiserror::Error;
 //!
@@ -14,8 +14,6 @@
 //!     Unknown,
 //! }
 //!
-//! impl ErrorIter for Error {}
-//!
 //! fn do_something() {
 //!     let error = Error::from(IoError::new(ErrorKind::Other, "oh no!"));
 //!
@@ -54,7 +52,7 @@ pub trait ErrorIter: std::error::Error + Sized + 'static {
     /// Create an iterator over the error and its recursive sources.
     ///
     /// ```
-    /// use error_iter::ErrorIter;
+    /// use error_iter::ErrorIter as _;
     /// use thiserror::Error;
     ///
     /// #[derive(Debug, Error)]
@@ -66,8 +64,6 @@ pub trait ErrorIter: std::error::Error + Sized + 'static {
     ///     Leaf,
     /// }
     ///
-    /// impl ErrorIter for Error {}
-    ///
     /// let error = Error::Nested(Box::new(Error::Leaf));
     ///
     /// let mut iter = error.sources();
@@ -82,6 +78,8 @@ pub trait ErrorIter: std::error::Error + Sized + 'static {
     }
 }
 
+impl<T> ErrorIter for T where T: std::error::Error + Sized + 'static {}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -96,8 +94,6 @@ mod tests {
         Leaf,
     }
 
-    impl ErrorIter for Error {}
-
     #[test]
     fn iter_sources_ok() {
         let error = Error::Nested(Box::new(Error::Nested(Box::new(Error::Leaf))));