Auto merge of #48516 - petrochenkov:stabsl, r=nikomatsakis

Stabilize slice patterns without `..`

And merge `feature(advanced_slice_patterns)` into `feature(slice_patterns)`.

The detailed description can be found in https://github.com/rust-lang/rust/issues/48836.

Slice patterns were unstable for long time since before 1.0 due to many bugs in the implementation, now this stabilization is possible primarily due to work of @arielb1 who [wrote the new MIR-based implementation of slice patterns](https://github.com/rust-lang/rust/pull/32202) and @mikhail-m1 who [fixed one remaining class of codegen issues](https://github.com/rust-lang/rust/pull/47926).

Reference PR https://github.com/rust-lang-nursery/reference/pull/259
cc https://github.com/rust-lang/rust/issues/23121
fixes #48836

src/doc/unstable-book/src/language-features/advanced-slice-patterns.md

@@ -1,35 +0,0 @@
-# `advanced_slice_patterns`
-
-The tracking issue for this feature is: [#23121]
-
-[#23121]: https://github.com/rust-lang/rust/issues/23121
-
-See also [`slice_patterns`](language-features/slice-patterns.html).
-
-------------------------
-
-
-The `advanced_slice_patterns` gate lets you use `..` to indicate any number of
-elements inside a pattern matching a slice. This wildcard can only be used once
-for a given array. If there's an identifier before the `..`, the result of the
-slice will be bound to that name. For example:
-
-```rust
-#![feature(advanced_slice_patterns, slice_patterns)]
-
-fn is_symmetric(list: &[u32]) -> bool {
-    match list {
-        &[] | &[_] => true,
-        &[x, ref inside.., y] if x == y => is_symmetric(inside),
-        _ => false
-    }
-}
-
-fn main() {
-    let sym = &[0, 1, 4, 2, 4, 1, 0];
-    assert!(is_symmetric(sym));
-
-    let not_sym = &[0, 1, 7, 2, 4, 1, 0];
-    assert!(!is_symmetric(not_sym));
-}
-```

src/doc/unstable-book/src/language-features/slice-patterns.md

@@ -4,25 +4,29 @@ The tracking issue for this feature is: [#23121]
 
 [#23121]: https://github.com/rust-lang/rust/issues/23121
 
-See also
-[`advanced_slice_patterns`](language-features/advanced-slice-patterns.html).
-
 ------------------------
 
-
+The `slice_patterns` feature gate lets you use `..` to indicate any number of
-If you want to match against a slice or array, you can use `&` with the
+elements inside a pattern matching a slice. This wildcard can only be used once
-`slice_patterns` feature:
+for a given array. If there's an pattern before the `..`, the subslice will be
+matched against that pattern. For example:
 
 ```rust
 #![feature(slice_patterns)]
 
-fn main() {
+fn is_symmetric(list: &[u32]) -> bool {
-    let v = vec!["match_this", "1"];
+    match list {
-
+        &[] | &[_] => true,
-    match &v[..] {
+        &[x, ref inside.., y] if x == y => is_symmetric(inside),
-        &["match_this", second] => println!("The second element is {}", second),
+        &[..] => false,
-        _ => {},
     }
 }
-```
 
+fn main() {
+    let sym = &[0, 1, 4, 2, 4, 1, 0];
+    assert!(is_symmetric(sym));
+
+    let not_sym = &[0, 1, 7, 2, 4, 1, 0];
+    assert!(!is_symmetric(not_sym));
+}
+```

src/liballoc/lib.rs

@@ -111,7 +111,6 @@
 #![feature(ptr_internals)]
 #![feature(rustc_attrs)]
 #![feature(slice_get_slice)]
-#![feature(slice_patterns)]
 #![feature(slice_rsplit)]
 #![feature(specialization)]
 #![feature(staged_api)]

src/libcore/benches/lib.rs

@@ -11,7 +11,6 @@
 #![deny(warnings)]
 
 #![feature(flt2dec)]
-#![feature(slice_patterns)]
 #![feature(test)]
 
 extern crate core;

src/libcore/tests/lib.rs

@@ -37,6 +37,7 @@
 #![feature(raw)]
 #![feature(refcell_replace_swap)]
 #![feature(slice_patterns)]
+#![feature(slice_rotate)]
 #![feature(sort_internals)]
 #![feature(specialization)]
 #![feature(step_trait)]

src/librustc/benches/lib.rs

@@ -10,7 +10,6 @@
 
 #![deny(warnings)]
 
-#![feature(slice_patterns)]
 #![feature(test)]
 
 extern crate test;

src/librustc_apfloat/lib.rs

@@ -47,7 +47,7 @@
 #![forbid(unsafe_code)]
 
 #![feature(i128_type)]
-#![feature(slice_patterns)]
+#![cfg_attr(stage0, feature(slice_patterns))]
 #![feature(try_from)]
 
 // See librustc_cratesio_shim/Cargo.toml for a comment explaining this.

src/librustc_const_eval/lib.rs

@@ -20,7 +20,6 @@
 #![deny(warnings)]
 
 #![feature(rustc_diagnostic_macros)]
-#![feature(slice_patterns)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(macro_lifetime_matcher)]

src/librustc_lint/lib.rs

@@ -31,7 +31,6 @@
 #![feature(macro_vis_matcher)]
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
-#![feature(slice_patterns)]
 #![cfg_attr(stage0, feature(never_type))]
 
 #[macro_use]

src/librustc_trans/lib.rs

@@ -30,7 +30,7 @@
 #![feature(libc)]
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
-#![feature(slice_patterns)]
+#![cfg_attr(stage0, feature(slice_patterns))]
 #![feature(conservative_impl_trait)]
 #![feature(optin_builtin_traits)]
 #![feature(inclusive_range_fields)]

src/librustc_trans_utils/lib.rs

@@ -24,7 +24,6 @@
 #![feature(i128_type)]
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
-#![feature(slice_patterns)]
 #![feature(conservative_impl_trait)]
 
 extern crate ar;

src/librustc_typeck/diagnostics.rs

@@ -3559,8 +3559,6 @@ elements in the array being matched.
 Example of erroneous code:
 
 ```compile_fail,E0527
-#![feature(slice_patterns)]
-
 let r = &[1, 2, 3, 4];
 match r {
     &[a, b] => { // error: pattern requires 2 elements but array
@@ -3625,8 +3623,6 @@ An array or slice pattern was matched against some other type.
 Example of erroneous code:
 
 ```compile_fail,E0529
-#![feature(slice_patterns)]
-
 let r: f32 = 1.0;
 match r {
     [a, b] => { // error: expected an array or slice, found `f32`
@@ -3639,8 +3635,6 @@ Ensure that the pattern and the expression being matched on are of consistent
 types:
 
 ```
-#![feature(slice_patterns)]
-
 let r = [1.0, 2.0];
 match r {
     [a, b] => { // ok!

src/librustc_typeck/lib.rs

@@ -72,7 +72,7 @@ This API is completely unstable and subject to change.
 
 #![allow(non_camel_case_types)]
 
-#![feature(advanced_slice_patterns)]
+#![cfg_attr(stage0, feature(advanced_slice_patterns))]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(conservative_impl_trait)]

src/librustdoc/lib.rs

@@ -20,7 +20,7 @@
 #![feature(box_syntax)]
 #![feature(fs_read_write)]
 #![feature(set_stdio)]
-#![feature(slice_patterns)]
+#![cfg_attr(stage0, feature(slice_patterns))]
 #![feature(test)]
 #![feature(unicode)]
 #![feature(vec_remove_item)]

src/libsyntax/feature_gate.rs

@@ -145,7 +145,6 @@ declare_features! (
     // rustc internal
     (active, rustc_diagnostic_macros, "1.0.0", None, None),
     (active, rustc_const_unstable, "1.0.0", None, None),
-    (active, advanced_slice_patterns, "1.0.0", Some(23121), None),
     (active, box_syntax, "1.0.0", Some(27779), None),
     (active, placement_in_syntax, "1.0.0", Some(27779), None),
     (active, unboxed_closures, "1.0.0", Some(29625), None),
@@ -474,6 +473,8 @@ declare_features! (
     (removed, allocator, "1.0.0", None, None),
     // Allows the `#[simd]` attribute -- removed in favor of `#[repr(simd)]`
     (removed, simd, "1.0.0", Some(27731), None),
+    // Merged into `slice_patterns`
+    (removed, advanced_slice_patterns, "1.0.0", Some(23121), None),
 );
 
 declare_features! (
@@ -1655,17 +1656,10 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 
     fn visit_pat(&mut self, pattern: &'a ast::Pat) {
         match pattern.node {
-            PatKind::Slice(_, Some(_), ref last) if !last.is_empty() => {
+            PatKind::Slice(_, Some(ref subslice), _) => {
-                gate_feature_post!(&self, advanced_slice_patterns,
-                                  pattern.span,
-                                  "multiple-element slice matches anywhere \
-                                   but at the end of a slice (e.g. \
-                                   `[0, ..xs, 0]`) are experimental")
-            }
-            PatKind::Slice(..) => {
                 gate_feature_post!(&self, slice_patterns,
-                                  pattern.span,
+                                   subslice.span,
-                                  "slice pattern syntax is experimental");
+                                   "syntax for subslices in slice patterns is not yet stabilized");
             }
             PatKind::Box(..) => {
                 gate_feature_post!(&self, box_patterns,

src/libsyntax/parse/parser.rs

@@ -3618,7 +3618,7 @@ impl<'a> Parser<'a> {
                         slice = Some(P(Pat {
                             id: ast::DUMMY_NODE_ID,
                             node: PatKind::Wild,
-                            span: self.span,
+                            span: self.prev_span,
                         }));
                         before_slice = false;
                     }

src/test/compile-fail/borrowck/borrowck-describe-lvalue.rs

@@ -13,7 +13,6 @@
 //[mir]compile-flags: -Z borrowck=mir
 
 #![feature(slice_patterns)]
-#![feature(advanced_slice_patterns)]
 
 pub struct Foo {
   x: u32

src/test/compile-fail/borrowck/borrowck-match-binding-is-assignment.rs

@@ -13,8 +13,6 @@
 
 // Test that immutable pattern bindings cannot be reassigned.
 
-#![feature(slice_patterns)]
-
 enum E {
     Foo(isize)
 }

src/test/compile-fail/borrowck/borrowck-move-out-from-array.rs

@@ -11,7 +11,8 @@
 // revisions: ast mir
 //[mir]compile-flags: -Z borrowck=mir
 
-#![feature(box_syntax, slice_patterns, advanced_slice_patterns)]
+#![feature(box_syntax)]
+#![feature(slice_patterns)]
 
 fn move_out_from_begin_and_end() {
     let a = [box 1, box 2];

src/test/compile-fail/borrowck/borrowck-vec-pattern-element-loan.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 fn a<'a>() -> &'a [isize] {

src/test/compile-fail/issue-12369.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 #![feature(slice_patterns)]
-#![allow(unused_variables)]
 #![deny(unreachable_patterns)]
 
 fn main() {

src/test/compile-fail/issue-13482-2.rs

@@ -10,8 +10,6 @@
 
 // compile-flags:-Z verbose
 
-#![feature(slice_patterns)]
-
 fn main() {
     let x = [1,2];
     let y = match x {

src/test/compile-fail/issue-13482.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn main() {
   let x = [1,2];
   let y = match x {

src/test/compile-fail/issue-15381.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn main() {
     let values: Vec<u8> = vec![1,2,3,4,5,6,7,8];
 

src/test/compile-fail/issue-41255.rs

@@ -10,7 +10,6 @@
 
 // Matching against float literals should result in a linter error
 
-#![feature(slice_patterns)]
 #![feature(exclusive_range_pattern)]
 #![allow(unused)]
 #![forbid(illegal_floating_point_literal_pattern)]

src/test/compile-fail/issue-6804.rs

@@ -10,7 +10,6 @@
 
 // Matching against NaN should result in a warning
 
-#![feature(slice_patterns)]
 #![allow(unused)]
 #![deny(illegal_floating_point_literal_pattern)]
 

src/test/compile-fail/match-byte-array-patterns-2.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns, slice_patterns)]
-
 fn main() {
     let buf = &[0, 1, 2, 3];
 

src/test/compile-fail/match-byte-array-patterns.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns, slice_patterns)]
+#![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
 
 fn main() {

src/test/compile-fail/match-ref-ice.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
 
 // The arity of `ref x` is always 1. If the pattern is compared to some non-structural type whose

src/test/compile-fail/match-slice-patterns.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns, slice_patterns)]
+#![feature(slice_patterns)]
 
 fn check(list: &[Option<()>]) {
     match list {

src/test/compile-fail/match-vec-fixed.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
 
 fn a() {

src/test/compile-fail/match-vec-mismatch-2.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn main() {
     match () {
         [()] => { }

src/test/compile-fail/match-vec-unreachable.rs

@@ -10,7 +10,6 @@
 
 #![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
-#![allow(unused_variables)]
 
 fn main() {
     let x: Vec<(isize, isize)> = Vec::new();

src/test/compile-fail/move-out-of-slice-1.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns, box_patterns)]
+#![feature(box_patterns)]
 
 struct A;
 

src/test/compile-fail/regions-pattern-typing-issue-19552.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn assert_static<T: 'static>(_t: T) {}
 
 fn main() {

src/test/compile-fail/uninhabited-matches-feature-gated.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 enum Void {}
 
 fn main() {

src/test/compile-fail/uninhabited-patterns.rs

@@ -9,9 +9,9 @@
 // except according to those terms.
 
 #![feature(box_patterns)]
-#![feature(slice_patterns)]
 #![feature(box_syntax)]
 #![feature(exhaustive_patterns)]
+#![feature(slice_patterns)]
 #![deny(unreachable_patterns)]
 
 mod foo {

src/test/mir-opt/uniform_array_move_out.rs

@@ -8,7 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(box_syntax, slice_patterns, advanced_slice_patterns)]
+#![feature(box_syntax)]
+#![feature(slice_patterns)]
 
 fn move_out_from_end() {
     let a = [box 1, box 2];

src/test/run-pass-fulldeps/auxiliary/roman_numerals.rs

@@ -12,7 +12,6 @@
 
 #![crate_type="dylib"]
 #![feature(plugin_registrar, rustc_private)]
-#![feature(slice_patterns)]
 
 extern crate syntax;
 extern crate syntax_pos;

src/test/run-pass/destructure-array-1.rs

@@ -11,9 +11,6 @@
 // Ensure that we can do a destructuring bind of a fixed-size array,
 // even when the element type has a destructor.
 
-
-#![feature(slice_patterns)]
-
 struct D { x: u8 }
 
 impl Drop for D { fn drop(&mut self) { } }

src/test/run-pass/dynamic-drop.rs

@@ -13,7 +13,8 @@
 
 // ignore-wasm32-bare compiled with panic=abort by default
 
-#![feature(generators, generator_trait, untagged_unions, slice_patterns, advanced_slice_patterns)]
+#![feature(generators, generator_trait, untagged_unions)]
+#![feature(slice_patterns)]
 
 use std::cell::{Cell, RefCell};
 use std::ops::Generator;

src/test/run-pass/ignore-all-the-things.rs

@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 struct Foo(isize, isize, isize, isize);
@@ -20,11 +19,11 @@ pub fn main() {
     let Foo(..) = Foo(5, 5, 5, 5);
     let Foo(..) = Foo(5, 5, 5, 5);
     let Bar{..} = Bar{a: 5, b: 5, c: 5, d: 5};
-    //let (..) = (5, 5, 5, 5);
+    let (..) = (5, 5, 5, 5);
-    //let Foo(a, b, ..) = Foo(5, 5, 5, 5);
+    let Foo(a, b, ..) = Foo(5, 5, 5, 5);
-    //let Foo(.., d) = Foo(5, 5, 5, 5);
+    let Foo(.., d) = Foo(5, 5, 5, 5);
-    //let (a, b, ..) = (5, 5, 5, 5);
+    let (a, b, ..) = (5, 5, 5, 5);
-    //let (.., c, d) = (5, 5, 5, 5);
+    let (.., c, d) = (5, 5, 5, 5);
     let Bar{b: b, ..} = Bar{a: 5, b: 5, c: 5, d: 5};
     match [5, 5, 5, 5] {
         [..] => { }

src/test/run-pass/issue-13027.rs

@@ -12,8 +12,6 @@
 // Tests that match expression handles overlapped literal and range
 // properly in the presence of guard function.
 
-#![feature(slice_patterns)]
-
 fn val() -> usize { 1 }
 
 static CONST: usize = 1;

src/test/run-pass/issue-15080.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
 #![feature(slice_patterns)]
 
 fn main() {

src/test/run-pass/issue-15104.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
 #![feature(slice_patterns)]
 
 fn main() {

src/test/run-pass/issue-16648.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(slice_patterns)]
-
 fn main() {
     let x: (isize, &[isize]) = (2, &[1, 2]);
     assert_eq!(match x {

src/test/run-pass/issue-17877.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
 #![feature(slice_patterns)]
 
 fn main() {

src/test/run-pass/issue-37598.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns, slice_patterns)]
+#![feature(slice_patterns)]
 
 fn check(list: &[u8]) {
     match list {

src/test/run-pass/issue-38002.rs

@@ -10,8 +10,6 @@
 
 // Check that constant ADTs are translated OK, part k of N.
 
-#![feature(slice_patterns)]
-
 enum Bar {
     C
 }

src/test/run-pass/issue-46855.rs

@@ -10,8 +10,6 @@
 
 // compile-flags: -Zmir-opt-level=1
 
-#![feature(slice_patterns)]
-
 use std::mem;
 
 #[derive(Copy, Clone)]

src/test/run-pass/issue-7784.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 use std::ops::Add;

src/test/run-pass/match-vec-alternatives.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 fn match_vecs<'a, T>(l1: &'a [T], l2: &'a [T]) -> &'static str {

src/test/run-pass/rfc-2005-default-binding-mode/slice.rs

@@ -8,8 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
 #![feature(match_default_bindings)]
+#![feature(slice_patterns)]
 
 fn slice_pat() {
     let sl: &[u8] = b"foo";

src/test/run-pass/trailing-comma.rs

@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(advanced_slice_patterns,)]
 #![feature(slice_patterns)]
 
 fn f<T,>(_: T,) {}

src/test/run-pass/vec-matching-autoslice.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(slice_patterns)]
-
 pub fn main() {
     let x = [1, 2, 3];
     match x {

src/test/run-pass/vec-matching-fixed.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 fn a() {

src/test/run-pass/vec-matching-fold.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 use std::fmt::Debug;

src/test/run-pass/vec-matching.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 fn a() {

src/test/run-pass/vec-tail-matching.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-
 #![feature(slice_patterns)]
 
 struct Foo {

src/test/ui/borrowck/borrowck-vec-pattern-nesting.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(slice_patterns)]

src/test/ui/borrowck/borrowck-vec-pattern-nesting.stderr

@@ -1,5 +1,5 @@
 error[E0506]: cannot assign to `vec[..]` because it is borrowed
-  --> $DIR/borrowck-vec-pattern-nesting.rs:21:13
+  --> $DIR/borrowck-vec-pattern-nesting.rs:20:13
    |
 LL |         [box ref _a, _, _] => {
    |              ------ borrow of `vec[..]` occurs here
@@ -8,7 +8,7 @@ LL |             vec[0] = box 4; //~ ERROR cannot assign
    |             ^^^^^^^^^^^^^^ assignment to borrowed `vec[..]` occurs here
 
 error[E0506]: cannot assign to `vec[..]` because it is borrowed
-  --> $DIR/borrowck-vec-pattern-nesting.rs:33:13
+  --> $DIR/borrowck-vec-pattern-nesting.rs:32:13
    |
 LL |         &mut [ref _b..] => {
    |               ------ borrow of `vec[..]` occurs here
@@ -17,7 +17,7 @@ LL |             vec[0] = box 4; //~ ERROR cannot assign
    |             ^^^^^^^^^^^^^^ assignment to borrowed `vec[..]` occurs here
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:43:14
+  --> $DIR/borrowck-vec-pattern-nesting.rs:42:14
    |
 LL |           &mut [_a, //~ ERROR cannot move out
    |                ^-- hint: to prevent move, use `ref _a` or `ref mut _a`
@@ -30,7 +30,7 @@ LL | |         ] => {
    | |_________^ cannot move out of here
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:56:13
+  --> $DIR/borrowck-vec-pattern-nesting.rs:55:13
    |
 LL |     let a = vec[0]; //~ ERROR cannot move out
    |             ^^^^^^
@@ -39,7 +39,7 @@ LL |     let a = vec[0]; //~ ERROR cannot move out
    |             help: consider using a reference instead: `&vec[0]`
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:64:14
+  --> $DIR/borrowck-vec-pattern-nesting.rs:63:14
    |
 LL |           &mut [ //~ ERROR cannot move out
    |  ______________^
@@ -50,7 +50,7 @@ LL | |          _b] => {}
    |            hint: to prevent move, use `ref _b` or `ref mut _b`
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:69:13
+  --> $DIR/borrowck-vec-pattern-nesting.rs:68:13
    |
 LL |     let a = vec[0]; //~ ERROR cannot move out
    |             ^^^^^^
@@ -59,7 +59,7 @@ LL |     let a = vec[0]; //~ ERROR cannot move out
    |             help: consider using a reference instead: `&vec[0]`
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:77:14
+  --> $DIR/borrowck-vec-pattern-nesting.rs:76:14
    |
 LL |         &mut [_a, _b, _c] => {}  //~ ERROR cannot move out
    |              ^--^^--^^--^
@@ -70,7 +70,7 @@ LL |         &mut [_a, _b, _c] => {}  //~ ERROR cannot move out
    |              cannot move out of here
 
 error[E0508]: cannot move out of type `[std::boxed::Box<isize>]`, a non-copy slice
-  --> $DIR/borrowck-vec-pattern-nesting.rs:81:13
+  --> $DIR/borrowck-vec-pattern-nesting.rs:80:13
    |
 LL |     let a = vec[0]; //~ ERROR cannot move out
    |             ^^^^^^

src/test/ui/error-codes/E0527.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn main() {
     let r = &[1, 2, 3, 4];
     match r {

src/test/ui/error-codes/E0527.stderr

@@ -1,5 +1,5 @@
 error[E0527]: pattern requires 2 elements but array has 4
-  --> $DIR/E0527.rs:16:10
+  --> $DIR/E0527.rs:14:10
    |
 LL |         &[a, b] => {
    |          ^^^^^^ expected 4 elements

src/test/ui/error-codes/E0529.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 fn main() {
     let r: f32 = 1.0;
     match r {

src/test/ui/error-codes/E0529.stderr

@@ -1,5 +1,5 @@
 error[E0529]: expected an array or slice, found `f32`
-  --> $DIR/E0529.rs:16:9
+  --> $DIR/E0529.rs:14:9
    |
 LL |         [a, b] => {
    |         ^^^^^^ pattern cannot match with input type `f32`

src/test/ui/feature-gate-advanced-slice-features.rs

@@ -1,22 +0,0 @@
-// Copyright 2014 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.
-
-// gate-test-advanced_slice_patterns
-
-#![feature(slice_patterns)]
-
-fn main() {
-    let x = [ 1, 2, 3, 4, 5 ];
-    match x {
-        [ xs.., 4, 5 ] => {}    //~ ERROR multiple-element slice matches
-        [ 1, xs.., 5 ] => {}    //~ ERROR multiple-element slice matches
-        [ 1, 2, xs.. ] => {}    // OK without feature gate
-    }
-}

src/test/ui/feature-gate-advanced-slice-features.stderr

@@ -1,19 +0,0 @@
-error[E0658]: multiple-element slice matches anywhere but at the end of a slice (e.g. `[0, ..xs, 0]`) are experimental (see issue #23121)
-  --> $DIR/feature-gate-advanced-slice-features.rs:18:9
-   |
-LL |         [ xs.., 4, 5 ] => {}    //~ ERROR multiple-element slice matches
-   |         ^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(advanced_slice_patterns)] to the crate attributes to enable
-
-error[E0658]: multiple-element slice matches anywhere but at the end of a slice (e.g. `[0, ..xs, 0]`) are experimental (see issue #23121)
-  --> $DIR/feature-gate-advanced-slice-features.rs:19:9
-   |
-LL |         [ 1, xs.., 5 ] => {}    //~ ERROR multiple-element slice matches
-   |         ^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(advanced_slice_patterns)] to the crate attributes to enable
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/feature-gate-slice-patterns.rs

@@ -8,11 +8,20 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// Test that slice pattern syntax is gated by `slice_patterns` feature gate
+// Test that slice pattern syntax with `..` is gated by `slice_patterns` feature gate
 
 fn main() {
     let x = [1, 2, 3, 4, 5];
     match x {
-        [1, 2, xs..] => {} //~ ERROR slice pattern syntax is experimental
+        [1, 2, ..] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+        [1, .., 5] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+        [.., 4, 5] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+    }
+
+    let x = [ 1, 2, 3, 4, 5 ];
+    match x {
+        [ xs.., 4, 5 ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+        [ 1, xs.., 5 ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+        [ 1, 2, xs.. ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
     }
 }

src/test/ui/feature-gate-slice-patterns.stderr

@@ -1,11 +1,51 @@
-error[E0658]: slice pattern syntax is experimental (see issue #23121)
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
-  --> $DIR/feature-gate-slice-patterns.rs:16:9
+  --> $DIR/feature-gate-slice-patterns.rs:16:16
    |
-LL |         [1, 2, xs..] => {} //~ ERROR slice pattern syntax is experimental
+LL |         [1, 2, ..] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
-   |         ^^^^^^^^^^^^
+   |                ^^
    |
    = help: add #![feature(slice_patterns)] to the crate attributes to enable
 
-error: aborting due to previous error
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
+  --> $DIR/feature-gate-slice-patterns.rs:17:13
+   |
+LL |         [1, .., 5] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+   |             ^^
+   |
+   = help: add #![feature(slice_patterns)] to the crate attributes to enable
+
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
+  --> $DIR/feature-gate-slice-patterns.rs:18:10
+   |
+LL |         [.., 4, 5] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+   |          ^^
+   |
+   = help: add #![feature(slice_patterns)] to the crate attributes to enable
+
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
+  --> $DIR/feature-gate-slice-patterns.rs:23:11
+   |
+LL |         [ xs.., 4, 5 ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+   |           ^^
+   |
+   = help: add #![feature(slice_patterns)] to the crate attributes to enable
+
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
+  --> $DIR/feature-gate-slice-patterns.rs:24:14
+   |
+LL |         [ 1, xs.., 5 ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+   |              ^^
+   |
+   = help: add #![feature(slice_patterns)] to the crate attributes to enable
+
+error[E0658]: syntax for subslices in slice patterns is not yet stabilized (see issue #23121)
+  --> $DIR/feature-gate-slice-patterns.rs:25:17
+   |
+LL |         [ 1, 2, xs.. ] => {} //~ ERROR syntax for subslices in slice patterns is not yet stabilized
+   |                 ^^
+   |
+   = help: add #![feature(slice_patterns)] to the crate attributes to enable
+
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0658`.

src/test/ui/mismatched_types/issue-38371.rs

@@ -7,8 +7,6 @@
 // <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)]
-
 
 struct Foo {
 }

src/test/ui/mismatched_types/issue-38371.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-38371.rs:16:8
+  --> $DIR/issue-38371.rs:14:8
    |
 LL | fn foo(&foo: Foo) { //~ ERROR mismatched types
    |        ^^^^ expected struct `Foo`, found reference
@@ -9,7 +9,7 @@ LL | fn foo(&foo: Foo) { //~ ERROR mismatched types
    = help: did you mean `foo: &Foo`?
 
 error[E0308]: mismatched types
-  --> $DIR/issue-38371.rs:30:9
+  --> $DIR/issue-38371.rs:28:9
    |
 LL | fn agh(&&bar: &u32) { //~ ERROR mismatched types
    |         ^^^^ expected u32, found reference
@@ -19,7 +19,7 @@ LL | fn agh(&&bar: &u32) { //~ ERROR mismatched types
    = help: did you mean `bar: &u32`?
 
 error[E0308]: mismatched types
-  --> $DIR/issue-38371.rs:33:8
+  --> $DIR/issue-38371.rs:31:8
    |
 LL | fn bgh(&&bar: u32) { //~ ERROR mismatched types
    |        ^^^^^ expected u32, found reference
@@ -28,7 +28,7 @@ LL | fn bgh(&&bar: u32) { //~ ERROR mismatched types
               found type `&_`
 
 error[E0529]: expected an array or slice, found `u32`
-  --> $DIR/issue-38371.rs:36:9
+  --> $DIR/issue-38371.rs:34:9
    |
 LL | fn ugh(&[bar]: &u32) { //~ ERROR expected an array or slice
    |         ^^^^^ pattern cannot match with input type `u32`

src/test/ui/non-exhaustive-pattern-witness.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(advanced_slice_patterns)]
 #![feature(slice_patterns)]
 
 struct Foo {

src/test/ui/non-exhaustive-pattern-witness.stderr

@@ -1,41 +1,41 @@
 error[E0004]: non-exhaustive patterns: `Foo { first: false, second: Some([_, _, _, _]) }` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:20:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:19:11
    |
 LL |     match (Foo { first: true, second: None }) {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pattern `Foo { first: false, second: Some([_, _, _, _]) }` not covered
 
 error[E0004]: non-exhaustive patterns: `Red` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:36:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:35:11
    |
 LL |     match Color::Red {
    |           ^^^^^^^^^^ pattern `Red` not covered
 
 error[E0004]: non-exhaustive patterns: `East`, `South` and `West` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:48:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:47:11
    |
 LL |     match Direction::North {
    |           ^^^^^^^^^^^^^^^^ patterns `East`, `South` and `West` not covered
 
 error[E0004]: non-exhaustive patterns: `Second`, `Third`, `Fourth` and 8 more not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:59:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:58:11
    |
 LL |     match ExcessiveEnum::First {
    |           ^^^^^^^^^^^^^^^^^^^^ patterns `Second`, `Third`, `Fourth` and 8 more not covered
 
 error[E0004]: non-exhaustive patterns: `CustomRGBA { a: true, .. }` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:67:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:66:11
    |
 LL |     match Color::Red {
    |           ^^^^^^^^^^ pattern `CustomRGBA { a: true, .. }` not covered
 
 error[E0004]: non-exhaustive patterns: `[Second(true), Second(false)]` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:83:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:82:11
    |
 LL |     match *x {
    |           ^^ pattern `[Second(true), Second(false)]` not covered
 
 error[E0004]: non-exhaustive patterns: `((), false)` not covered
-  --> $DIR/non-exhaustive-pattern-witness.rs:96:11
+  --> $DIR/non-exhaustive-pattern-witness.rs:95:11
    |
 LL |     match ((), false) {
    |           ^^^^^^^^^^^ pattern `((), false)` not covered

src/test/ui/pat-slice-old-style.rs

@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
-
 // NB: this test was introduced in #23121 and will have to change when default match binding modes
 // stabilizes.
 
+#![feature(slice_patterns)]
+
 fn slice_pat(x: &[u8]) {
     // OLD!
     match x {

src/test/ui/rfc-2005-default-binding-mode/slice.rs

@@ -8,8 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
 #![feature(match_default_bindings)]
+#![feature(slice_patterns)]
 
 pub fn main() {
     let sl: &[u8] = b"foo";