---

yaml
---
r: 34643
b: refs/heads/master
c: d81196c
h: refs/heads/master
i:
  34641: 81641c5
  34639: 2a9ee15
v: v3

Author: graydon

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 9cba4af24366b6c08299e709fac26361d7920ccb
+refs/heads/master: d81196ce96b1d3da7bb718ed4c5e9d4810be896e
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: eb8fd119c65c67f3b1b8268cc7341c22d39b7b61
 refs/heads/try: d324a424d8f84b1eb049b12cf34182bda91b0024

trunk/doc/rust.md

@@ -1157,9 +1157,14 @@ The definition expression of a constant is limited to expression forms that can
 
 ### Traits
 
-A _trait item_ describes a set of method types. [_implementation
-items_](#implementations) can be used to provide implementations of
-those methods for a specific type.
+A _trait_ describes a set of method types.
+
+Traits can include default implementations of methods,
+written in terms of some unknown [`self` type](#self-types);
+the `self` type may either be completely unspecified,
+or constrained by some other [trait type](#trait-types).
+
+Traits are implemented for specific types through separate [implementations](#implementations).
 
 ~~~~
 # type surface = int;
@@ -1171,10 +1176,9 @@ trait shape {
 }
 ~~~~
 
-This defines a trait with two methods. All values that have
-[implementations](#implementations) of this trait in scope can
-have their `draw` and `bounding_box` methods called, using
-`value.bounding_box()` [syntax](#field-expressions).
+This defines a trait with two methods.
+All values that have [implementations](#implementations) of this trait in scope can have their `draw` and `bounding_box` methods called,
+using `value.bounding_box()` [syntax](#field-expressions).
 
 Type parameters can be specified for a trait to make it generic.
 These appear after the name, using the same syntax used in [generic