rollup merge of #20416: nikomatsakis/coherence

Conflicts:
	src/test/run-pass/issue-15734.rs
	src/test/run-pass/issue-3743.rs

src/libserialize/json.rs

@@ -76,12 +76,13 @@
 //! Create a struct called `TestStruct` and serialize and deserialize it to and from JSON using the
 //! serialization API, using the derived serialization code.
 //!
-//! ```rust
+//! ```notrust
+//! // FIXME(#19470): this cannot be ```rust``` because it fails orphan checking at the moment
 //! extern crate serialize;
 //! use serialize::json;
 //!
 //! // Automatically generate `Decodable` and `Encodable` trait implementations
-//! #[deriving(Decodable, Encodable)]
+//! #[deriving(RustcDecodable, RustcEncodable)]
 //! pub struct TestStruct  {
 //!     data_int: u8,
 //!     data_str: String,
@@ -110,7 +111,8 @@
 //!
 //! ### Simple example of `ToJson` usage
 //!
-//! ```rust
+//! ```notrust
+//! // FIXME(#19470): this cannot be ```rust``` because it fails orphan checking at the moment
 //! extern crate serialize;
 //! use serialize::json::{mod, ToJson, Json};
 //!
@@ -149,7 +151,8 @@
 //!
 //! ### Verbose example of `ToJson` usage
 //!
-//! ```rust
+//! ```notrust
+//! // FIXME(#19470): this cannot be ```rust``` because it fails orphan checking at the moment
 //! extern crate serialize;
 //! use std::collections::BTreeMap;
 //! use serialize::json::{mod, Json, ToJson};