Auto merge of #32202 - arielb1:slice-patterns, r=nikomatsakis

Implement RFC495 semantics for slice patterns

non-MIR translation is still not supported for these and will happily ICE.

This is a [breaking-change] for many uses of slice_patterns.

[RFC 495 text](https://github.com/rust-lang/rfcs/blob/master/text/0495-array-pattern-changes.md)

31 files changed, 313 insertions, 116 deletions

diff --git a/src/test/compile-fail/borrowck/borrowck-move-out-of-vec-tail.rs b/src/test/compile-fail/borrowck/borrowck-move-out-of-vec-tail.rs
index 15771295743..f595d9d81cc 100644
--- a/src/test/compile-fail/borrowck/borrowck-move-out-of-vec-tail.rs
+++ b/src/test/compile-fail/borrowck/borrowck-move-out-of-vec-tail.rs
@@ -24,14 +24,14 @@ pub fn main() {
         Foo { string: "baz".to_string() }
     );
     let x: &[Foo] = &x;
-    match x {
-        [_, tail..] => {
+    match *x {
+        [_, ref tail..] => {
             match tail {
-                [Foo { string: a },
+                &[Foo { string: a },
                 //~^ ERROR cannot move out of borrowed content
                 //~| cannot move out
                 //~| to prevent move
-                 Foo { string: b }] => {
+                  Foo { string: b }] => {
                     //~^ NOTE and here
                 }
                 _ => {
diff --git a/src/test/compile-fail/borrowck/borrowck-vec-pattern-element-loan.rs b/src/test/compile-fail/borrowck/borrowck-vec-pattern-element-loan.rs
index 98052ad31a7..63e80b90ac8 100644
--- a/src/test/compile-fail/borrowck/borrowck-vec-pattern-element-loan.rs
+++ b/src/test/compile-fail/borrowck/borrowck-vec-pattern-element-loan.rs
@@ -15,7 +15,7 @@ fn a<'a>() -> &'a [isize] {
     let vec = vec!(1, 2, 3, 4);
     let vec: &[isize] = &vec; //~ ERROR does not live long enough
     let tail = match vec {
-        [_, tail..] => tail,
+        &[_, ref tail..] => tail,
         _ => panic!("a")
     };
     tail
@@ -25,7 +25,7 @@ fn b<'a>() -> &'a [isize] {
     let vec = vec!(1, 2, 3, 4);
     let vec: &[isize] = &vec; //~ ERROR does not live long enough
     let init = match vec {
-        [init.., _] => init,
+        &[ref init.., _] => init,
         _ => panic!("b")
     };
     init
@@ -35,7 +35,7 @@ fn c<'a>() -> &'a [isize] {
     let vec = vec!(1, 2, 3, 4);
     let vec: &[isize] = &vec; //~ ERROR does not live long enough
     let slice = match vec {
-        [_, slice.., _] => slice,
+        &[_, ref slice.., _] => slice,
         _ => panic!("c")
     };
     slice
diff --git a/src/test/compile-fail/borrowck/borrowck-vec-pattern-loan-from-mut.rs b/src/test/compile-fail/borrowck/borrowck-vec-pattern-loan-from-mut.rs
index db635893c81..9dfd4d77928 100644
--- a/src/test/compile-fail/borrowck/borrowck-vec-pattern-loan-from-mut.rs
+++ b/src/test/compile-fail/borrowck/borrowck-vec-pattern-loan-from-mut.rs
@@ -14,7 +14,7 @@ fn a() {
     let mut v = vec!(1, 2, 3);
     let vb: &mut [isize] = &mut v;
     match vb {
-        [_a, tail..] => {
+        &mut [_a, ref tail..] => {
             v.push(tail[0] + tail[1]); //~ ERROR cannot borrow
         }
         _ => {}
diff --git a/src/test/compile-fail/borrowck/borrowck-vec-pattern-move-tail.rs b/src/test/compile-fail/borrowck/borrowck-vec-pattern-move-tail.rs
index 97dcaeb0bf1..fddb9838c44 100644
--- a/src/test/compile-fail/borrowck/borrowck-vec-pattern-move-tail.rs
+++ b/src/test/compile-fail/borrowck/borrowck-vec-pattern-move-tail.rs
@@ -13,7 +13,7 @@
 fn main() {
     let mut a = [1, 2, 3, 4];
     let t = match a {
-        [1, 2, tail..] => tail,
+        [1, 2, ref tail..] => tail,
         _ => unreachable!()
     };
     println!("t[0]: {}", t[0]);
diff --git a/src/test/compile-fail/borrowck/borrowck-vec-pattern-nesting.rs b/src/test/compile-fail/borrowck/borrowck-vec-pattern-nesting.rs
index eec6c8473eb..d89b4100789 100644
--- a/src/test/compile-fail/borrowck/borrowck-vec-pattern-nesting.rs
+++ b/src/test/compile-fail/borrowck/borrowck-vec-pattern-nesting.rs
@@ -28,7 +28,7 @@ fn b() {
     let mut vec = vec!(box 1, box 2, box 3);
     let vec: &mut [Box<isize>] = &mut vec;
     match vec {
-        [_b..] => {
+        &mut [ref _b..] => {
         //~^ borrow of `vec[..]` occurs here
             vec[0] = box 4; //~ ERROR cannot assign
             //~^ assignment to borrowed `vec[..]` occurs here
@@ -40,10 +40,11 @@ fn c() {
     let mut vec = vec!(box 1, box 2, box 3);
     let vec: &mut [Box<isize>] = &mut vec;
     match vec {
-        [_a,         //~ ERROR cannot move out
-        //~| cannot move out
-        //~| to prevent move
-         _b..] => {
+        &mut [_a, //~ ERROR cannot move out of borrowed content
+            //~| cannot move out
+            //~| to prevent move
+            ..
+        ] => {
             // Note: `_a` is *moved* here, but `b` is borrowing,
             // hence illegal.
             //
@@ -61,7 +62,7 @@ fn d() {
     let mut vec = vec!(box 1, box 2, box 3);
     let vec: &mut [Box<isize>] = &mut vec;
     match vec {
-        [_a..,     //~ ERROR cannot move out
+        &mut [ //~ ERROR cannot move out
         //~^ cannot move out
          _b] => {} //~ NOTE to prevent move
         _ => {}
@@ -75,7 +76,7 @@ fn e() {
     let mut vec = vec!(box 1, box 2, box 3);
     let vec: &mut [Box<isize>] = &mut vec;
     match vec {
-        [_a, _b, _c] => {}  //~ ERROR cannot move out
+        &mut [_a, _b, _c] => {}  //~ ERROR cannot move out
         //~| cannot move out
         //~| NOTE to prevent move
         //~| NOTE and here
diff --git a/src/test/compile-fail/borrowck/borrowck-vec-pattern-tail-element-loan.rs b/src/test/compile-fail/borrowck/borrowck-vec-pattern-tail-element-loan.rs
index 82b3490d7d7..a849e4e2faf 100644
--- a/src/test/compile-fail/borrowck/borrowck-vec-pattern-tail-element-loan.rs
+++ b/src/test/compile-fail/borrowck/borrowck-vec-pattern-tail-element-loan.rs
@@ -14,7 +14,7 @@ fn a<'a>() -> &'a isize {
     let vec = vec!(1, 2, 3, 4);
     let vec: &[isize] = &vec; //~ ERROR `vec` does not live long enough
     let tail = match vec {
-        [_a, tail..] => &tail[0],
+        &[_a, ref tail..] => &tail[0],
         _ => panic!("foo")
     };
     tail
diff --git a/src/test/compile-fail/issue-12369.rs b/src/test/compile-fail/issue-12369.rs
index 1333bfac64e..978d6f59b2d 100644
--- a/src/test/compile-fail/issue-12369.rs
+++ b/src/test/compile-fail/issue-12369.rs
@@ -13,9 +13,9 @@
 fn main() {
     let sl = vec![1,2,3];
     let v: isize = match &*sl {
-        [] => 0,
-        [a,b,c] => 3,
-        [a, rest..] => a,
-        [10,a, rest..] => 10 //~ ERROR: unreachable pattern
+        &[] => 0,
+        &[a,b,c] => 3,
+        &[a, ref rest..] => a,
+        &[10,a, ref rest..] => 10 //~ ERROR: unreachable pattern
     };
 }
diff --git a/src/test/compile-fail/issue-12567.rs b/src/test/compile-fail/issue-12567.rs
index 1580ec00f94..32a6ea4f062 100644
--- a/src/test/compile-fail/issue-12567.rs
+++ b/src/test/compile-fail/issue-12567.rs
@@ -12,13 +12,15 @@
 
 fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) {
     match (l1, l2) {
-        ([], []) => println!("both empty"),
-        ([], [hd, tl..]) | ([hd, tl..], []) => println!("one empty"),
-        //~^ ERROR: cannot move out of borrowed content
+        (&[], &[]) => println!("both empty"),
+        (&[], &[hd, ..]) | (&[hd, ..], &[])
+            => println!("one empty"),
         //~^^ ERROR: cannot move out of borrowed content
-        ([hd1, tl1..], [hd2, tl2..]) => println!("both nonempty"),
-        //~^ ERROR: cannot move out of borrowed content
+        //~^^^ ERROR: cannot move out of borrowed content
+        (&[hd1, ..], &[hd2, ..])
+            => println!("both nonempty"),
         //~^^ ERROR: cannot move out of borrowed content
+        //~^^^ ERROR: cannot move out of borrowed content
     }
 }
 
diff --git a/src/test/compile-fail/issue-13482-2.rs b/src/test/compile-fail/issue-13482-2.rs
index fe03373a45d..6885c8d94c6 100644
--- a/src/test/compile-fail/issue-13482-2.rs
+++ b/src/test/compile-fail/issue-13482-2.rs
@@ -15,11 +15,7 @@
 fn main() {
     let x = [1,2];
     let y = match x {
-        [] => None,
-//~^ ERROR mismatched types
-//~| expected type `[_#1i; 2]`
-//~| found type `[_#7t; 0]`
-//~| expected an array with a fixed size of 2 elements, found one with 0 elements
+        [] => None, //~ ERROR pattern requires 0 elements but array has 2
         [a,_] => Some(a)
     };
 }
diff --git a/src/test/compile-fail/issue-13482.rs b/src/test/compile-fail/issue-13482.rs
index 7ed7f5898b1..82e82df3186 100644
--- a/src/test/compile-fail/issue-13482.rs
+++ b/src/test/compile-fail/issue-13482.rs
@@ -13,11 +13,7 @@
 fn main() {
   let x = [1,2];
   let y = match x {
-    [] => None,
-    //~^ ERROR mismatched types
-    //~| expected type `[_; 2]`
-    //~| found type `[_; 0]`
-    //~| expected an array with a fixed size of 2 elements
+    [] => None, //~ ERROR pattern requires 0 elements but array has 2
     [a,_] => Some(a)
   };
 }
diff --git a/src/test/compile-fail/issue-15381.rs b/src/test/compile-fail/issue-15381.rs
index ec29a84f44e..d0964d2aabe 100644
--- a/src/test/compile-fail/issue-15381.rs
+++ b/src/test/compile-fail/issue-15381.rs
@@ -13,8 +13,8 @@
 fn main() {
     let values: Vec<u8> = vec![1,2,3,4,5,6,7,8];
 
-    for [x,y,z] in values.chunks(3).filter(|&xs| xs.len() == 3) {
-        //~^ ERROR refutable pattern in `for` loop binding: `[]` not covered
+    for &[x,y,z] in values.chunks(3).filter(|&xs| xs.len() == 3) {
+        //~^ ERROR refutable pattern in `for` loop binding: `&[]` not covered
         println!("y={}", y);
     }
 }
diff --git a/src/test/compile-fail/issue-30240.rs b/src/test/compile-fail/issue-30240.rs
new file mode 100644
index 00000000000..9b105e7ec15
--- /dev/null
+++ b/src/test/compile-fail/issue-30240.rs
@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    match "world" { //~ ERROR non-exhaustive patterns: `&_`
+        "hello" => {}
+    }
+
+    match "world" { //~ ERROR non-exhaustive patterns: `&_`
+        ref _x if false => {}
+        "hello" => {}
+        "hello" => {} //~ ERROR unreachable pattern
+    }
+}
diff --git a/src/test/compile-fail/match-vec-mismatch-2.rs b/src/test/compile-fail/match-vec-mismatch-2.rs
index 2831499c73d..375d855d1fd 100644
--- a/src/test/compile-fail/match-vec-mismatch-2.rs
+++ b/src/test/compile-fail/match-vec-mismatch-2.rs
@@ -13,9 +13,6 @@
 fn main() {
     match () {
         [()] => { }
-        //~^ ERROR mismatched types
-        //~| expected type `()`
-        //~| found type `&[_]`
-        //~| expected (), found &-ptr
+        //~^ ERROR expected an array or slice, found `()`
     }
 }
diff --git a/src/test/compile-fail/match-vec-mismatch.rs b/src/test/compile-fail/match-vec-mismatch.rs
index ef75213d34b..3ac4958e7db 100644
--- a/src/test/compile-fail/match-vec-mismatch.rs
+++ b/src/test/compile-fail/match-vec-mismatch.rs
@@ -12,7 +12,36 @@
 
 fn main() {
     match "foo".to_string() {
-        ['f', 'o', ..] => {} //~ ERROR mismatched types
+        ['f', 'o', ..] => {}
+        //~^ ERROR expected an array or slice, found `std::string::String`
         _ => { }
-    }
+    };
+
+    match &[0, 1, 2] {
+        [..] => {} //~ ERROR expected an array or slice, found `&[_; 3]`
+    };
+
+    match &[0, 1, 2] {
+        &[..] => {} // ok
+    };
+
+    match [0, 1, 2] {
+        [0] => {}, //~ ERROR pattern requires
+
+        [0, 1, x..] => {
+            let a: [_; 1] = x;
+        }
+        [0, 1, 2, 3, x..] => {} //~ ERROR pattern requires
+    };
+
+    match does_not_exist { //~ ERROR unresolved name
+        [] => {}
+    };
+}
+
+fn another_fn_to_avoid_suppression() {
+    match Default::default()
+    {
+        [] => {}  //~ ERROR the type of this value
+    };
 }
diff --git a/src/test/compile-fail/match-vec-unreachable.rs b/src/test/compile-fail/match-vec-unreachable.rs
index 48b70b4bda0..57e3a58b566 100644
--- a/src/test/compile-fail/match-vec-unreachable.rs
+++ b/src/test/compile-fail/match-vec-unreachable.rs
@@ -13,7 +13,7 @@
 fn main() {
     let x: Vec<(isize, isize)> = Vec::new();
     let x: &[(isize, isize)] = &x;
-    match x {
+    match *x {
         [a, (2, 3), _] => (),
         [(1, 2), (2, 3), b] => (), //~ ERROR unreachable pattern
         _ => ()
@@ -23,7 +23,7 @@ fn main() {
                               "bar".to_string(),
                               "baz".to_string()];
     let x: &[String] = &x;
-    match x {
+    match *x {
         [a, _, _, ..] => { println!("{}", a); }
         [_, _, _, _, _] => { } //~ ERROR unreachable pattern
         _ => { }
@@ -31,8 +31,8 @@ fn main() {
 
     let x: Vec<char> = vec!('a', 'b', 'c');
     let x: &[char] = &x;
-    match x {
-        ['a', 'b', 'c', _tail..] => {}
+    match *x {
+        ['a', 'b', 'c', ref _tail..] => {}
         ['a', 'b', 'c'] => {} //~ ERROR unreachable pattern
         _ => {}
     }
diff --git a/src/test/compile-fail/non-exhaustive-match-nested.rs b/src/test/compile-fail/non-exhaustive-match-nested.rs
index ad2b8c400e5..1d524217a12 100644
--- a/src/test/compile-fail/non-exhaustive-match-nested.rs
+++ b/src/test/compile-fail/non-exhaustive-match-nested.rs
@@ -14,11 +14,11 @@ enum t { a(u), b }
 enum u { c, d }
 
 fn match_nested_vecs<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
-    match (l1, l2) { //~ ERROR non-exhaustive patterns: `(Some([]), Err(_))` not covered
-        (Some([]), Ok([])) => "Some(empty), Ok(empty)",
-        (Some([_, ..]), Ok(_)) | (Some([_, ..]), Err(())) => "Some(non-empty), any",
-        (None, Ok([])) | (None, Err(())) | (None, Ok([_])) => "None, Ok(less than one element)",
-        (None, Ok([_, _, ..])) => "None, Ok(at least two elements)"
+    match (l1, l2) { //~ ERROR non-exhaustive patterns: `(Some(&[]), Err(_))` not covered
+        (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
+        (Some(&[_, ..]), Ok(_)) | (Some(&[_, ..]), Err(())) => "Some(non-empty), any",
+        (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
+        (None, Ok(&[_, _, ..])) => "None, Ok(at least two elements)"
     }
 }
 
diff --git a/src/test/compile-fail/non-exhaustive-match.rs b/src/test/compile-fail/non-exhaustive-match.rs
index b9749c2696e..017baacc9d3 100644
--- a/src/test/compile-fail/non-exhaustive-match.rs
+++ b/src/test/compile-fail/non-exhaustive-match.rs
@@ -39,20 +39,20 @@ fn main() {
     }
     let vec = vec!(Some(42), None, Some(21));
     let vec: &[Option<isize>] = &vec;
-    match vec { //~ ERROR non-exhaustive patterns: `[]` not covered
-        [Some(..), None, tail..] => {}
-        [Some(..), Some(..), tail..] => {}
+    match *vec { //~ ERROR non-exhaustive patterns: `[]` not covered
+        [Some(..), None, ref tail..] => {}
+        [Some(..), Some(..), ref tail..] => {}
         [None] => {}
     }
     let vec = vec!(1);
     let vec: &[isize] = &vec;
-    match vec {
-        [_, tail..] => (),
+    match *vec {
+        [_, ref tail..] => (),
         [] => ()
     }
     let vec = vec!(0.5f32);
     let vec: &[f32] = &vec;
-    match vec { //~ ERROR non-exhaustive patterns: `[_, _, _, _]` not covered
+    match *vec { //~ ERROR non-exhaustive patterns: `[_, _, _, _]` not covered
         [0.1, 0.2, 0.3] => (),
         [0.1, 0.2] => (),
         [0.1] => (),
@@ -60,11 +60,11 @@ fn main() {
     }
     let vec = vec!(Some(42), None, Some(21));
     let vec: &[Option<isize>] = &vec;
-    match vec {
-        [Some(..), None, tail..] => {}
-        [Some(..), Some(..), tail..] => {}
-        [None, None, tail..] => {}
-        [None, Some(..), tail..] => {}
+    match *vec {
+        [Some(..), None, ref tail..] => {}
+        [Some(..), Some(..), ref tail..] => {}
+        [None, None, ref tail..] => {}
+        [None, Some(..), ref tail..] => {}
         [Some(_)] => {}
         [None] => {}
         [] => {}
diff --git a/src/test/compile-fail/non-exhaustive-pattern-witness.rs b/src/test/compile-fail/non-exhaustive-pattern-witness.rs
index b986878f783..0b12a9acbcb 100644
--- a/src/test/compile-fail/non-exhaustive-pattern-witness.rs
+++ b/src/test/compile-fail/non-exhaustive-pattern-witness.rs
@@ -80,7 +80,7 @@ enum Enum {
 
 fn vectors_with_nested_enums() {
     let x: &'static [Enum] = &[Enum::First, Enum::Second(false)];
-    match x {
+    match *x {
     //~^ ERROR non-exhaustive patterns: `[Second(true), Second(false)]` not covered
         [] => (),
         [_] => (),
@@ -88,7 +88,7 @@ fn vectors_with_nested_enums() {
         [Enum::Second(true), Enum::First] => (),
         [Enum::Second(true), Enum::Second(true)] => (),
         [Enum::Second(false), _] => (),
-        [_, _, tail.., _] => ()
+        [_, _, ref tail.., _] => ()
     }
 }
 
diff --git a/src/test/compile-fail/pat-slice-old-style.rs b/src/test/compile-fail/pat-slice-old-style.rs
new file mode 100644
index 00000000000..ccb25d859ac
--- /dev/null
+++ b/src/test/compile-fail/pat-slice-old-style.rs
@@ -0,0 +1,22 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(slice_patterns)]
+
+fn slice_pat(x: &[u8]) {
+    // OLD!
+    match x {
+        [a, b..] => {}
+        //~^ ERROR expected an array or slice, found `&[u8]`
+        //~| HELP the semantics of slice patterns changed recently; see issue #23121
+    }
+}
+
+fn main() {}
diff --git a/src/test/run-pass/issue-15080.rs b/src/test/run-pass/issue-15080.rs
index 7b00ea4a520..cee0caeb465 100644
--- a/src/test/run-pass/issue-15080.rs
+++ b/src/test/run-pass/issue-15080.rs
@@ -16,12 +16,12 @@ fn main() {
 
     let mut result = vec!();
     loop {
-        x = match x {
-            [1, n, 3, rest..] => {
+        x = match *x {
+            [1, n, 3, ref rest..] => {
                 result.push(n);
                 rest
             }
-            [n, rest..] => {
+            [n, ref rest..] => {
                 result.push(n);
                 rest
             }
diff --git a/src/test/run-pass/issue-15104.rs b/src/test/run-pass/issue-15104.rs
index b55754ee59b..508360cb701 100644
--- a/src/test/run-pass/issue-15104.rs
+++ b/src/test/run-pass/issue-15104.rs
@@ -16,9 +16,9 @@ fn main() {
 }
 
 fn count_members(v: &[usize]) -> usize {
-    match v {
+    match *v {
         []         => 0,
         [_]        => 1,
-        [_x, xs..] => 1 + count_members(xs)
+        [_, ref xs..] => 1 + count_members(xs)
     }
 }
diff --git a/src/test/run-pass/issue-16648.rs b/src/test/run-pass/issue-16648.rs
index 384bd9df7cf..e596bee8bfe 100644
--- a/src/test/run-pass/issue-16648.rs
+++ b/src/test/run-pass/issue-16648.rs
@@ -9,14 +9,15 @@
 // except according to those terms.
 
 
-#![feature(slice_patterns)]
+#![feature(slice_patterns, rustc_attrs)]
 
+#[rustc_mir]
 fn main() {
     let x: (isize, &[isize]) = (2, &[1, 2]);
     assert_eq!(match x {
-        (0, [_, _]) => 0,
+        (0, &[_, _]) => 0,
         (1, _) => 1,
-        (2, [_, _]) => 2,
+        (2, &[_, _]) => 2,
         (2, _) => 3,
         _ => 4
     }, 2);
diff --git a/src/test/run-pass/issue-30240.rs b/src/test/run-pass/issue-30240.rs
new file mode 100644
index 00000000000..3be661ce35e
--- /dev/null
+++ b/src/test/run-pass/issue-30240.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    let &ref a = &[0i32] as &[_];
+    assert_eq!(a, &[0i32] as &[_]);
+
+    let &ref a = "hello";
+    assert_eq!(a, "hello");
+
+    match "foo" {
+        "fool" => unreachable!(),
+        "foo" => {},
+        ref _x => unreachable!()
+    }
+}
diff --git a/src/test/run-pass/issue-7784.rs b/src/test/run-pass/issue-7784.rs
index badc013cd62..0008825226b 100644
--- a/src/test/run-pass/issue-7784.rs
+++ b/src/test/run-pass/issue-7784.rs
@@ -11,6 +11,7 @@
 
 #![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
+#![feature(rustc_attrs)]
 
 use std::ops::Add;
 
@@ -21,6 +22,7 @@ fn bar(a: &'static str, b: &'static str) -> [&'static str; 4] {
     [a, b, b, a]
 }
 
+#[rustc_mir]
 fn main() {
     assert_eq!(foo([1, 2, 3]), (1, 3, 6));
 
diff --git a/src/test/run-pass/match-unsized.rs b/src/test/run-pass/match-unsized.rs
new file mode 100644
index 00000000000..7253672a7ff
--- /dev/null
+++ b/src/test/run-pass/match-unsized.rs
@@ -0,0 +1,18 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    let data: &'static str = "Hello, World!";
+    match data {
+        &ref xs => {
+            assert_eq!(data, xs);
+        }
+    }
+}
diff --git a/src/test/run-pass/match-vec-alternatives.rs b/src/test/run-pass/match-vec-alternatives.rs
index 43e0b442251..010c1455210 100644
--- a/src/test/run-pass/match-vec-alternatives.rs
+++ b/src/test/run-pass/match-vec-alternatives.rs
@@ -11,47 +11,53 @@
 
 #![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
+#![feature(rustc_attrs)]
 
+#[rustc_mir]
 fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
     match (l1, l2) {
-        ([], []) => "both empty",
-        ([], [..]) | ([..], []) => "one empty",
-        ([..], [..]) => "both non-empty"
+        (&[], &[]) => "both empty",
+        (&[], &[..]) | (&[..], &[]) => "one empty",
+        (&[..], &[..]) => "both non-empty"
     }
 }
 
+#[rustc_mir]
 fn match_vecs_cons<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
     match (l1, l2) {
-        ([], []) => "both empty",
-        ([], [_, ..]) | ([_, ..], []) => "one empty",
-        ([_, ..], [_, ..]) => "both non-empty"
+        (&[], &[]) => "both empty",
+        (&[], &[_, ..]) | (&[_, ..], &[]) => "one empty",
+        (&[_, ..], &[_, ..]) => "both non-empty"
     }
 }
 
+#[rustc_mir]
 fn match_vecs_snoc<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {
     match (l1, l2) {
-        ([], []) => "both empty",
-        ([], [.., _]) | ([.., _], []) => "one empty",
-        ([.., _], [.., _]) => "both non-empty"
+        (&[], &[]) => "both empty",
+        (&[], &[.., _]) | (&[.., _], &[]) => "one empty",
+        (&[.., _], &[.., _]) => "both non-empty"
     }
 }
 
+#[rustc_mir]
 fn match_nested_vecs_cons<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
     match (l1, l2) {
-        (Some([]), Ok([])) => "Some(empty), Ok(empty)",
-        (Some([_, ..]), Ok(_)) | (Some([_, ..]), Err(())) => "Some(non-empty), any",
-        (None, Ok([])) | (None, Err(())) | (None, Ok([_])) => "None, Ok(less than one element)",
-        (None, Ok([_, _, ..])) => "None, Ok(at least two elements)",
+        (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
+        (Some(&[_, ..]), Ok(_)) | (Some(&[_, ..]), Err(())) => "Some(non-empty), any",
+        (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
+        (None, Ok(&[_, _, ..])) => "None, Ok(at least two elements)",
         _ => "other"
     }
 }
 
+#[rustc_mir]
 fn match_nested_vecs_snoc<'a, T>(l1: Option<&'a [T]>, l2: Result<&'a [T], ()>) -> &'static str {
     match (l1, l2) {
-        (Some([]), Ok([])) => "Some(empty), Ok(empty)",
-        (Some([.., _]), Ok(_)) | (Some([.., _]), Err(())) => "Some(non-empty), any",
-        (None, Ok([])) | (None, Err(())) | (None, Ok([_])) => "None, Ok(less than one element)",
-        (None, Ok([.., _, _])) => "None, Ok(at least two elements)",
+        (Some(&[]), Ok(&[])) => "Some(empty), Ok(empty)",
+        (Some(&[.., _]), Ok(_)) | (Some(&[.., _]), Err(())) => "Some(non-empty), any",
+        (None, Ok(&[])) | (None, Err(())) | (None, Ok(&[_])) => "None, Ok(less than one element)",
+        (None, Ok(&[.., _, _])) => "None, Ok(at least two elements)",
         _ => "other"
     }
 }
diff --git a/src/test/run-pass/vec-matching-fold.rs b/src/test/run-pass/vec-matching-fold.rs
index ee70ea58750..7a6129d311e 100644
--- a/src/test/run-pass/vec-matching-fold.rs
+++ b/src/test/run-pass/vec-matching-fold.rs
@@ -11,21 +11,28 @@
 
 #![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
+#![feature(rustc_attrs)]
 
+use std::fmt::Debug;
+
+#[rustc_mir(graphviz="mir.gv")]
 fn foldl<T, U, F>(values: &[T],
                   initial: U,
                   mut function: F)
                   -> U where
-    U: Clone,
+    U: Clone+Debug, T:Debug,
     F: FnMut(U, &T) -> U,
-{
-    match values {
-        [ref head, tail..] =>
+{    match values {
+        &[ref head, ref tail..] =>
             foldl(tail, function(initial, head), function),
-        [] => initial.clone()
+        &[] => {
+            // FIXME: call guards
+            let res = initial.clone(); res
+        }
     }
 }
 
+#[rustc_mir]
 fn foldr<T, U, F>(values: &[T],
                   initial: U,
                   mut function: F)
@@ -34,9 +41,12 @@ fn foldr<T, U, F>(values: &[T],
     F: FnMut(&T, U) -> U,
 {
     match values {
-        [head.., ref tail] =>
+        &[ref head.., ref tail] =>
             foldr(head, function(tail, initial), function),
-        [] => initial.clone()
+        &[] => {
+            // FIXME: call guards
+            let res = initial.clone(); res
+        }
     }
 }
 
diff --git a/src/test/run-pass/vec-matching-legal-tail-element-borrow.rs b/src/test/run-pass/vec-matching-legal-tail-element-borrow.rs
index e7553c8e157..1093bc7c18b 100644
--- a/src/test/run-pass/vec-matching-legal-tail-element-borrow.rs
+++ b/src/test/run-pass/vec-matching-legal-tail-element-borrow.rs
@@ -8,14 +8,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
+#![feature(slice_patterns, rustc_attrs)]
 
+#[rustc_mir]
 pub fn main() {
     let x = &[1, 2, 3, 4, 5];
     let x: &[isize] = &[1, 2, 3, 4, 5];
     if !x.is_empty() {
         let el = match x {
-            [1, ref tail..] => &tail[0],
+            &[1, ref tail..] => &tail[0],
             _ => unreachable!()
         };
         println!("{}", *el);
diff --git a/src/test/run-pass/vec-matching.rs b/src/test/run-pass/vec-matching.rs
index eedf27f8577..075709a63b5 100644
--- a/src/test/run-pass/vec-matching.rs
+++ b/src/test/run-pass/vec-matching.rs
@@ -11,7 +11,9 @@
 
 #![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
+#![feature(rustc_attrs)]
 
+#[rustc_mir]
 fn a() {
     let x = [1];
     match x {
@@ -21,6 +23,7 @@ fn a() {
     }
 }
 
+#[rustc_mir]
 fn b() {
     let x = [1, 2, 3];
     match x {
@@ -56,6 +59,48 @@ fn b() {
     }
 }
 
+
+#[rustc_mir]
+fn b_slice() {
+    let x : &[_] = &[1, 2, 3];
+    match x {
+        &[a, b, ref c..] => {
+            assert_eq!(a, 1);
+            assert_eq!(b, 2);
+            let expected: &[_] = &[3];
+            assert_eq!(c, expected);
+        }
+        _ => unreachable!()
+    }
+    match x {
+        &[ref a.., b, c] => {
+            let expected: &[_] = &[1];
+            assert_eq!(a, expected);
+            assert_eq!(b, 2);
+            assert_eq!(c, 3);
+        }
+        _ => unreachable!()
+    }
+    match x {
+        &[a, ref b.., c] => {
+            assert_eq!(a, 1);
+            let expected: &[_] = &[2];
+            assert_eq!(b, expected);
+            assert_eq!(c, 3);
+        }
+        _ => unreachable!()
+    }
+    match x {
+        &[a, b, c] => {
+            assert_eq!(a, 1);
+            assert_eq!(b, 2);
+            assert_eq!(c, 3);
+        }
+        _ => unreachable!()
+    }
+}
+
+#[rustc_mir]
 fn c() {
     let x = [1];
     match x {
@@ -64,6 +109,7 @@ fn c() {
     }
 }
 
+#[rustc_mir]
 fn d() {
     let x = [1, 2, 3];
     let branch = match x {
@@ -75,17 +121,40 @@ fn d() {
     assert_eq!(branch, 1);
 }
 
+#[rustc_mir]
 fn e() {
     let x: &[isize] = &[1, 2, 3];
-    match x {
-        [1, 2] => (),
-        [..] => ()
-    }
+    let a = match *x {
+        [1, 2] => 0,
+        [..] => 1,
+    };
+
+    assert_eq!(a, 1);
+
+    let b = match *x {
+        [2, ..] => 0,
+        [1, 2, ..] => 1,
+        [_] => 2,
+        [..] => 3
+    };
+
+    assert_eq!(b, 1);
+
+
+    let c = match *x {
+        [_, _, _, _, ..] => 0,
+        [1, 2, ..] => 1,
+        [_] => 2,
+        [..] => 3
+    };
+
+    assert_eq!(c, 1);
 }
 
 pub fn main() {
     a();
     b();
+    b_slice();
     c();
     d();
     e();
diff --git a/src/test/run-pass/vec-tail-matching.rs b/src/test/run-pass/vec-tail-matching.rs
index 6cc7e3a072c..6084a0d07a1 100644
--- a/src/test/run-pass/vec-tail-matching.rs
+++ b/src/test/run-pass/vec-tail-matching.rs
@@ -11,26 +11,28 @@
 
 
 #![feature(slice_patterns)]
+#![feature(rustc_attrs)]
 
 struct Foo {
-    string: String
+    string: &'static str
 }
 
+#[rustc_mir]
 pub fn main() {
     let x = [
-        Foo { string: "foo".to_string() },
-        Foo { string: "bar".to_string() },
-        Foo { string: "baz".to_string() }
+        Foo { string: "foo" },
+        Foo { string: "bar" },
+        Foo { string: "baz" }
     ];
     match x {
-        [ref first, tail..] => {
-            assert_eq!(first.string, "foo".to_string());
+        [ref first, ref tail..] => {
+            assert_eq!(first.string, "foo");
             assert_eq!(tail.len(), 2);
-            assert_eq!(tail[0].string, "bar".to_string());
-            assert_eq!(tail[1].string, "baz".to_string());
+            assert_eq!(tail[0].string, "bar");
+            assert_eq!(tail[1].string, "baz");
 
-            match tail {
-                [Foo { .. }, _, Foo { .. }, _tail..] => {
+            match *(tail as &[_]) {
+                [Foo { .. }, _, Foo { .. }, ref _tail..] => {
                     unreachable!();
                 }
                 [Foo { string: ref a }, Foo { string: ref b }] => {
diff --git a/src/test/run-pass/zero_sized_subslice_match.rs b/src/test/run-pass/zero_sized_subslice_match.rs
index 697508ae488..00f4aa98a3e 100644
--- a/src/test/run-pass/zero_sized_subslice_match.rs
+++ b/src/test/run-pass/zero_sized_subslice_match.rs
@@ -8,15 +8,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
+#![feature(rustc_attrs)]
 #![feature(slice_patterns)]
 
+#[rustc_mir]
 fn main() {
     let x = [(), ()];
 
     // The subslice used to go out of bounds for zero-sized array items, check that this doesn't
     // happen anymore
     match x {
-        [_, y..] => assert_eq!(&x[1] as *const (), &y[0] as *const ())
+        [_, ref y..] => assert_eq!(&x[1] as *const (), &y[0] as *const ())
     }
 }