From 422895ac8b7486dec2f659ab97c1036f89f6e173 Mon Sep 17 00:00:00 2001
From: Giang Nguyen <nguyengiangdev@gmail.com>
Date: Mon, 16 Jan 2017 15:06:30 +0700
Subject: [PATCH 1/3] Update grammar struct field init shorthand

---
 src/doc/grammar.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/doc/grammar.md b/src/doc/grammar.md
index 690d44cc2cb7b..3dc09d21e7eea 100644
--- a/src/doc/grammar.md
+++ b/src/doc/grammar.md
@@ -510,8 +510,9 @@ unit_expr : "()" ;
 ### Structure expressions
 
 ```antlr
-struct_expr : expr_path '{' ident ':' expr
-                      [ ',' ident ':' expr ] *
+field_init : ident | ident ':' expr;
+struct_expr : expr_path '{' field_init
+                      [ ',' field_init ] *
                       [ ".." expr ] '}' |
               expr_path '(' expr
                       [ ',' expr ] * ')' |

From 00650de1a8c323826eae558c304838b2795a3648 Mon Sep 17 00:00:00 2001
From: Giang Nguyen <nguyengiangdev@gmail.com>
Date: Mon, 16 Jan 2017 16:24:30 +0700
Subject: [PATCH 2/3] Add explain struct field init shorthand

---
 src/doc/reference.md | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/doc/reference.md b/src/doc/reference.md
index 4112b328f612e..9e821e53a7115 100644
--- a/src/doc/reference.md
+++ b/src/doc/reference.md
@@ -2757,6 +2757,19 @@ let base = Point3d {x: 1, y: 2, z: 3};
 Point3d {y: 0, z: 10, .. base};
 ```
 
+#### Struct field init shorthand
+
+When initializing a data structure (struct, enum, union) with named fields, allow writing `fieldname` as a shorthand for `fieldname: fieldname`. This allows a compact syntax for initialization, with less duplication.
+
+In the initializer for a `struct` with named fields, a `union` with named fields, or an enum variant with named fields, accept an identifier `field` as a shorthand for `field: field`.
+
+Example:
+
+```
+let a = SomeStruct { field1, field2: expression, field3 };
+let b = SomeStruct { field1: field1, field2: expression, field3: field3 };
+```
+
 ### Block expressions
 
 A _block expression_ is similar to a module in terms of the declarations that

From 66bc3ca0adc13cc5b33270effbc9b798d5e48114 Mon Sep 17 00:00:00 2001
From: Giang Nguyen <nguyengiangdev@gmail.com>
Date: Mon, 16 Jan 2017 16:58:07 +0700
Subject: [PATCH 3/3] Add doc field init shorthand

---
 src/doc/book/structs.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/doc/book/structs.md b/src/doc/book/structs.md
index cfd00cf997e0b..5a13746d0a87f 100644
--- a/src/doc/book/structs.md
+++ b/src/doc/book/structs.md
@@ -117,6 +117,28 @@ fn main() {
 }
 ```
 
+We can initializing a data structure (struct, enum, union) with named fields, by writing `fieldname` as a shorthand for `fieldname: fieldname`. This allows a compact syntax for initialization, with less duplication:
+
+```
+#![feature(field_init_shorthand)]
+
+#[derive(Debug)]
+struct Person<'a> {
+    name: &'a str,
+    age: u8
+}
+
+fn main() {
+    // Create struct with field init shorthand
+    let name = "Peter";
+    let age = 27;
+    let peter = Person { name, age };
+    
+    // Print debug struct
+    println!("{:?}", peter);
+}
+```
+
 # Update syntax
 
 A `struct` can include `..` to indicate that you want to use a copy of some