From f33c489154bf98ca4fae2555f3c90f92b2d55363 Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Fri, 24 Nov 2017 10:03:13 -0800
Subject: [PATCH] added default ErrorResponse for std::error::Error

---
 Cargo.toml   |  3 +++
 src/error.rs | 21 +++++++++++++++------
 src/lib.rs   |  4 ++++
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d7c55f765..40515fb1b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,6 +32,9 @@ tls = ["native-tls", "tokio-tls"]
 # openssl
 alpn = ["openssl", "openssl/v102", "openssl/v110", "tokio-openssl"]
 
+# nightly
+nightly = []
+
 [dependencies]
 log = "0.3"
 failure = "0.1"
diff --git a/src/error.rs b/src/error.rs
index d2808533b..8ad17daa5 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -4,12 +4,16 @@ use std::str::Utf8Error;
 use std::string::FromUtf8Error;
 use std::io::Error as IoError;
 
+#[cfg(feature="nightly")]
+use std::error::Error as StdError;
+
 use cookie;
 use httparse;
 use failure::Fail;
 use http2::Error as Http2Error;
 use http::{header, StatusCode, Error as HttpError};
 use http_range::HttpRangeParseError;
+use serde_json::error::Error as JsonError;
 
 // re-exports
 pub use cookie::{ParseError as CookieParseError};
@@ -64,18 +68,23 @@ impl From<Error> for HttpResponse {
     }
 }
 
+/// `Error` for any error that implements `ErrorResponse`
 impl<T: ErrorResponse> From<T> for Error {
     fn from(err: T) -> Error {
         Error { cause: Box::new(err) }
     }
 }
 
-// /// Default error is `InternalServerError`
-// impl<T: StdError + Sync + Send + 'static> ErrorResponse for T {
-//     fn error_response(&self) -> HttpResponse {
-//         HttpResponse::new(StatusCode::INTERNAL_SERVER_ERROR, Body::Empty)
-//     }
-// }
+/// Default error is `InternalServerError`
+#[cfg(feature="nightly")]
+default impl<T: StdError + Sync + Send + 'static> ErrorResponse for T {
+     fn error_response(&self) -> HttpResponse {
+         HttpResponse::new(StatusCode::INTERNAL_SERVER_ERROR, Body::Empty)
+     }
+}
+
+/// `InternalServerError` for `JsonError`
+impl ErrorResponse for JsonError {}
 
 /// A set of errors that can occur during parsing HTTP streams
 #[derive(Fail, Debug)]
diff --git a/src/lib.rs b/src/lib.rs
index c0463aee4..cbb30a950 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,9 @@
 //! Web framework for [Actix](https://github.com/actix/actix)
 
+#![cfg_attr(feature="nightly", feature(
+    specialization, // for impl ErrorResponse for std::error::Error
+))]
+
 #[macro_use]
 extern crate log;
 extern crate time;