---

yaml
---
r: 140748
b: refs/heads/try2
c: d43908a
h: refs/heads/master
v: v3

Author: huonw

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 8d4a3d58b7e06edf223f6cc51b9c61fcf6b49832
+refs/heads/try2: d43908a3a7b2889b847306070593f58b93ca1a6b
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/doc/rust.md

@@ -1425,6 +1425,8 @@ names are effectively reserved. Some significant attributes include:
 * The `test` attribute, for marking functions as unit tests.
 * The `allow`, `warn`, `forbid`, and `deny` attributes, for controlling lint checks. Lint checks supported
 by the compiler can be found via `rustc -W help`.
+* The `deriving` attribute, for automatically generating
+  implementations of certain traits.
 
 Other attributes may be added or removed during development of the language.
 
@@ -1526,6 +1528,47 @@ A complete list of the built-in language items follows:
 > **Note:** This list is likely to become out of date. We should auto-generate it
 > from `librustc/middle/lang_items.rs`.
 
+### Deriving
+
+The `deriving` attribute allows certain traits to be automatically
+implemented for data structures. For example, the following will
+create an `impl` for the `Eq` and `Clone` traits for `Foo`, the type
+parameter `T` will be given the `Eq` or `Clone` constraints for the
+appropriate `impl`:
+
+~~~
+#[deriving(Eq, Clone)]
+struct Foo<T> {
+    a: int,
+    b: T
+}
+~~~
+
+The generated `impl` for `Eq` is equivalent to
+
+~~~
+# struct Foo<T> { a: int, b: T }
+impl<T: Eq> Eq for Foo<T> {
+    fn eq(&self, other: &Foo<T>) -> bool {
+        self.a == other.a && self.b == other.b
+    }
+
+    fn ne(&self, other: &Foo<T>) -> bool {
+        self.a != other.a || self.b != other.b
+    }
+}
+~~~
+
+Supported traits for `deriving` are:
+
+* Comparison traits: `Eq`, `TotalEq`, `Ord`, `TotalOrd`.
+* Serialization: `Encodable`, `Decodable`. These require `std`.
+* `Clone`, to perform deep copies.
+* `IterBytes`, to iterate over the bytes in a data type.
+* `Rand`, to create a random instance of a data type.
+* `ToStr`, to convert to a string. For a type with this instance,
+  `obj.to_str()` has the same output as `fmt!("%?", obj)`.
+
 # Statements and expressions
 
 Rust is _primarily_ an expression language. This means that most forms of

branches/try2/doc/tutorial.md

@@ -2290,6 +2290,27 @@ let nonsense = mycircle.radius() * mycircle.area();
 
 > ***Note:*** Trait inheritance does not actually work with objects yet
 
+## Deriving implementations for traits
+
+A small number of traits in `core` and `std` can have implementations
+that can be automatically derived. These instances are specified by
+placing the `deriving` attribute on a data type declaration. For
+example, the following will mean that `Circle` has an implementation
+for `Eq` and can be used with the equality operators, and that a value
+of type `ABC` can be randomly generated and converted to a string:
+
+~~~
+#[deriving(Eq)]
+struct Circle { radius: float }
+
+#[deriving(Rand, ToStr)]
+enum ABC { A, B, C }
+~~~
+
+The full list of derivable traits is `Eq`, `TotalEq`, `Ord`,
+`TotalOrd`, `Encodable` `Decodable`, `Clone`, `IterBytes`, `Rand` and
+`ToStr`.
+
 # Modules and crates
 
 The Rust namespace is arranged in a hierarchy of modules. Each source

branches/try2/src/librustc/middle/trans/adt.rs

@@ -574,7 +574,7 @@ fn padding(size: u64) -> ValueRef {
 }
 
 // XXX this utility routine should be somewhere more general
-#[inline(always)]
+#[always_inline]
 fn roundup(x: u64, a: u64) -> u64 { ((x + (a - 1)) / a) * a }
 
 /// Get the discriminant of a constant value.  (Not currently used.)

branches/try2/src/rt/rust_globals.h

@@ -20,7 +20,7 @@
 #endif
 
 #if defined(__GNUC__)
-#define ALWAYS_INLINE __attribute__((always_inline)) INLINE
+#define ALWAYS_INLINE __attribute((always_inline)) INLINE
 #elif defined(_MSC_VER)
 #define ALWAYS_INLINE __forceinline
 #else