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]

1 files changed, 0 insertions, 30 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() {}