Stabilize use_nested_groups

Author: pietroalbini

src/doc/unstable-book/src/language-features/use-nested-groups.md

@@ -423,9 +423,6 @@ declare_features! (
     // In-band lifetime bindings (e.g. `fn foo(x: &'a u8) -> &'a u8`)
     (active, in_band_lifetimes, "1.23.0", Some(44524)),
 
-    // Nested groups in `use` (RFC 2128)
-    (active, use_nested_groups, "1.23.0", Some(44494)),
-
     // generic associated types (RFC 1598)
     (active, generic_associated_types, "1.23.0", Some(44265)),
 
@@ -544,6 +541,8 @@ declare_features! (
     (accepted, repr_align, "1.24.0", Some(33626)),
     // allow '|' at beginning of match arms (RFC 1925)
     (accepted, match_beginning_vert, "1.25.0", Some(44101)),
+    // Nested groups in `use` (RFC 2128)
+    (accepted, use_nested_groups, "1.25.0", Some(44494)),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must
@@ -1805,29 +1804,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
         visit::walk_path(self, path);
     }
 
-    fn visit_use_tree(&mut self, use_tree: &'a ast::UseTree, id: NodeId, nested: bool) {
-        if nested {
-            match use_tree.kind {
-                ast::UseTreeKind::Simple(_) => {
-                    if use_tree.prefix.segments.len() != 1 {
-                        gate_feature_post!(&self, use_nested_groups, use_tree.span,
-                                           "paths in `use` groups are experimental");
-                    }
-                }
-                ast::UseTreeKind::Glob => {
-                    gate_feature_post!(&self, use_nested_groups, use_tree.span,
-                                       "glob imports in `use` groups are experimental");
-                }
-                ast::UseTreeKind::Nested(_) => {
-                    gate_feature_post!(&self, use_nested_groups, use_tree.span,
-                                       "nested groups in `use` are experimental");
-                }
-            }
-        }
-
-        visit::walk_use_tree(self, use_tree, id);
-    }
-
     fn visit_vis(&mut self, vis: &'a ast::Visibility) {
         if let ast::Visibility::Crate(span, ast::CrateSugar::JustCrate) = *vis {
             gate_feature_post!(&self, crate_visibility_modifier, span,

src/libsyntax/feature_gate.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(use_nested_groups)]
 #![allow(unused_imports)]
 
 mod foo {}

src/test/compile-fail/absolute-paths-in-nested-use-groups.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(use_nested_groups)]
 #![allow(unused_import)]
 
 use {{}, {}};

src/test/run-pass/issue-47673.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(use_nested_groups)]
-
 mod a {
     pub enum B {}
 

src/test/run-pass/use-nested-groups.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(use_nested_groups)]
-
 mod a {
     pub mod b1 {
         pub enum C2 {}

src/test/ui/feature-gate-use_nested_groups.rs

@@ -1,7 +1,7 @@
 error[E0432]: unresolved import `a::b1::C1`
-  --> $DIR/use-nested-groups-error.rs:21:14
+  --> $DIR/use-nested-groups-error.rs:19:14
    |
-21 | use a::{b1::{C1, C2}, B2};
+19 | use a::{b1::{C1, C2}, B2};
    |              ^^ no `C1` in `a::b1`. Did you mean to use `C2`?
 
 error: aborting due to previous error