---

yaml
---
r: 223173
b: refs/heads/auto
c: 4277369
h: refs/heads/master
i:
  223171: 0bf5d23
v: v3

Author: lastorset

[refs]

@@ -8,7 +8,7 @@ refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503
 refs/tags/release-0.3.1: 495bae036dfe5ec6ceafd3312b4dca48741e845b
 refs/tags/release-0.4: e828ea2080499553b97dfe33b3f4d472b4562ad7
 refs/tags/release-0.5: 7e3bcfbf21278251ee936ad53e92e9b719702d73
-refs/heads/auto: 556b0815d779a50a151c44032febf3ce253e621e
+refs/heads/auto: 427736931bb1cd34c97e4e1f79a5a84430415207
 refs/tags/release-0.6: b4ebcfa1812664df5e142f0134a5faea3918544c
 refs/tags/0.1: b19db808c2793fe2976759b85a355c3ad8c8b336
 refs/tags/0.2: 1754d02027f2924bed83b0160ee340c7f41d5ea1

branches/auto/src/doc/trpl/generics.md

@@ -6,7 +6,7 @@ Generics are called ‘parametric polymorphism’ in type theory,
 which means that they are types or functions that have multiple forms (‘poly’
 is multiple, ‘morph’ is form) over a given parameter (‘parametric’).
 
-Anyway, enough with type theory, let’s check out some generic code. Rust’s
+Anyway, enough type theory, let’s check out some generic code. Rust’s
 standard library provides a type, `Option<T>`, that’s generic:
 
 ```rust
@@ -27,7 +27,7 @@ let x: Option<i32> = Some(5);
 
 In the type declaration, we say `Option<i32>`. Note how similar this looks to
 `Option<T>`. So, in this particular `Option`, `T` has the value of `i32`. On
-the right-hand side of the binding, we do make a `Some(T)`, where `T` is `5`.
+the right-hand side of the binding, we make a `Some(T)`, where `T` is `5`.
 Since that’s an `i32`, the two sides match, and Rust is happy. If they didn’t
 match, we’d get an error:
 

branches/auto/src/doc/trpl/traits.md

@@ -47,8 +47,11 @@ As you can see, the `trait` block looks very similar to the `impl` block,
 but we don’t define a body, just a type signature. When we `impl` a trait,
 we use `impl Trait for Item`, rather than just `impl Item`.
 
-We can use traits to constrain our generics. Consider this function, which
-does not compile:
+## Traits bounds for generic functions
+
+Traits are useful because they allow a type to make certain promises about its
+behavior. Generic functions can exploit this to constrain the types they
+accept. Consider this function, which does not compile:
 
 ```rust,ignore
 fn print_area<T>(shape: T) {
@@ -75,7 +78,7 @@ fn print_area<T: HasArea>(shape: T) {
 }
 ```
 
-The syntax `<T: HasArea>` means `any type that implements the HasArea trait`.
+The syntax `<T: HasArea>` means “any type that implements the `HasArea` trait.”
 Because traits define function type signatures, we can be sure that any type
 which implements `HasArea` will have an `.area()` method.
 
@@ -154,8 +157,8 @@ error: the trait `HasArea` is not implemented for the type `_` [E0277]
 
 ## Traits bounds for generic structs
 
-Trait constraints also can apply to implementations for generic structs.  Just
-append the constraint when you declare type parameters. Here is a new type
+Your generic structs can also benefit from trait constraints. All you need to
+do is append the constraint when you declare type parameters. Here is a new
 type `Rectangle<T>` and its operation `is_square()`:
 
 ```rust
@@ -232,7 +235,7 @@ impl HasArea for i32 {
 It is considered poor style to implement methods on such primitive types, even
 though it is possible.
 
-This may seem like the Wild West, but there are two other restrictions around
+This may seem like the Wild West, but there are two restrictions around
 implementing traits that prevent this from getting out of hand. The first is
 that if the trait isn’t defined in your scope, it doesn’t apply. Here’s an
 example: the standard library provides a [`Write`][write] trait which adds
@@ -397,10 +400,10 @@ This shows off the additional feature of `where` clauses: they allow bounds
 where the left-hand side is an arbitrary type (`i32` in this case), not just a
 plain type parameter (like `T`).
 
-## Default methods
+# Default methods
 
-There’s one last feature of traits we should cover: default methods. It’s
-easiest just to show an example:
+If you already know how a typical implementor will define a method, you can
+let your trait supply a default:
 
 ```rust
 trait Foo {