auto merge of #20514 : alexcrichton/rust/serialize-associated-type, r=aturon

This commit moves the libserialize crate (and will force the hand of the
rustc-serialize crate) to not require the `old_orphan_check` feature gate as
well as using associated types wherever possible. Concretely, the following
changes were made:

* The error type of `Encoder` and `Decoder` is now an associated type, meaning
  that these traits have no type parameters.

* The `Encoder` and `Decoder` type parameters on the `Encodable` and `Decodable`
  traits have moved to the corresponding method of the trait. This movement
  alleviates the dependency on `old_orphan_check` but implies that
  implementations can no longer be specialized for the type of encoder/decoder
  being implemented.

Due to the trait definitions changing, this is a:

[breaking-change]

4 files changed, 4 insertions, 40 deletions

diff --git a/src/test/compile-fail/variance-trait-matching-2.rs b/src/test/compile-fail/variance-trait-matching-2.rs
deleted file mode 100644
index cae7a4cefad..00000000000
--- a/src/test/compile-fail/variance-trait-matching-2.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-extern crate serialize;
-
-use std::fmt;
-use serialize::{Encodable, Encoder};
-
-pub fn buffer_encode<'a,
-                     T:Encodable<serialize::json::Encoder<'a>,fmt::Error>>(
-                     to_encode_object: &T)
-                     -> String {
-    let mut m = String::new();
-    {
-        let mut encoder =
-            serialize::json::Encoder::new(&mut m);
-        //~^ ERROR `m` does not live long enough
-        to_encode_object.encode(&mut encoder);
-    }
-    m
-}
-
-fn main() {}
diff --git a/src/test/run-pass/issue-11881.rs b/src/test/run-pass/issue-11881.rs
index 24deb7c2e4b..d0d8a8589a4 100644
--- a/src/test/run-pass/issue-11881.rs
+++ b/src/test/run-pass/issue-11881.rs
@@ -40,16 +40,10 @@ enum WireProtocol {
     // ...
 }
 
-fn encode_json<
-               T: for<'a> Encodable<json::Encoder<'a>,
-                            fmt::Error>>(val: &T,
-                                               wr: &mut SeekableMemWriter) {
+fn encode_json<T: Encodable>(val: &T, wr: &mut SeekableMemWriter) {
     write!(wr, "{}", json::as_json(val));
 }
-fn encode_rbml<'a,
-               T: Encodable<writer::Encoder<'a, SeekableMemWriter>,
-                            io::IoError>>(val: &T,
-                                               wr: &'a mut SeekableMemWriter) {
+fn encode_rbml<T: Encodable>(val: &T, wr: &mut SeekableMemWriter) {
     let mut encoder = writer::Encoder::new(wr);
     val.encode(&mut encoder);
 }
diff --git a/src/test/run-pass/issue-15924.rs b/src/test/run-pass/issue-15924.rs
index 1ab8deda383..db9f1cc9df7 100644
--- a/src/test/run-pass/issue-15924.rs
+++ b/src/test/run-pass/issue-15924.rs
@@ -21,7 +21,7 @@ struct Foo<T> {
 }
 
 #[unsafe_destructor]
-impl<T: for<'a> Encodable<json::Encoder<'a>, fmt::Error>> Drop for Foo<T> {
+impl<T: Encodable> Drop for Foo<T> {
     fn drop(&mut self) {
         json::encode(&self.v);
     }
diff --git a/src/test/run-pass/issue-4016.rs b/src/test/run-pass/issue-4016.rs
index e5cc8414f06..220332f6354 100644
--- a/src/test/run-pass/issue-4016.rs
+++ b/src/test/run-pass/issue-4016.rs
@@ -13,7 +13,7 @@ extern crate serialize;
 
 use serialize::{json, Decodable};
 
-trait JD : Decodable<json::Decoder, json::DecoderError> { }
+trait JD : Decodable {}
 
 fn exec<T: JD>() {
     let doc = json::from_str("").unwrap();