From bf6c007760169e9c382d3700fd1cdd20037e4343 Mon Sep 17 00:00:00 2001
From: Huon Wilson <dbau.pp+github@gmail.com>
Date: Fri, 5 Dec 2014 15:56:25 -0800
Subject: Change `&` pat to only work with &T, and `&mut` with &mut T.

This implements RFC 179 by making the pattern `&<pat>` require matching
against a variable of type `&T`, and introducing the pattern `&mut
<pat>` which only works with variables of type `&mut T`.

The pattern `&mut x` currently parses as `&(mut x)` i.e. a pattern match
through a `&T` or a `&mut T` that binds the variable `x` to have type
`T` and to be mutable. This should be rewritten as follows, for example,

    for &mut x in slice.iter() {

becomes

    for &x in slice.iter() {
        let mut x = x;

Due to this, this is a

[breaking-change]

Closes #20496.
---
 src/libsyntax/ast.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/libsyntax/ast.rs')

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index a33ee44be89..d61b7a17a93 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -556,7 +556,7 @@ pub enum Pat_ {
     PatStruct(Path, Vec<Spanned<FieldPat>>, bool),
     PatTup(Vec<P<Pat>>),
     PatBox(P<Pat>),
-    PatRegion(P<Pat>), // reference pattern
+    PatRegion(P<Pat>, Mutability), // reference pattern
     PatLit(P<Expr>),
     PatRange(P<Expr>, P<Expr>),
     /// [a, b, ..i, y, z] is represented as:
-- 
cgit 1.4.1-3-g733a5