rust-lang · traviscross · Feb 6, 2024
diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -120,14 +120,7 @@ impl<'a> PostExpansionVisitor<'a> {
         impl Visitor<'_> for ImplTraitVisitor<'_> {
             fn visit_ty(&mut self, ty: &ast::Ty) {
                 if let ast::TyKind::ImplTrait(..) = ty.kind {
-                    if self.in_associated_ty {
-                        gate!(
-                            &self.vis,
-                            impl_trait_in_assoc_type,
-                            ty.span,
-                            "`impl Trait` in associated types is unstable"
-                        );
-                    } else {
+                    if !self.in_associated_ty {
                         gate!(
                             &self.vis,
                             type_alias_impl_trait,

diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -14,7 +14,7 @@
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
-#![feature(impl_trait_in_assoc_type)]
+#![cfg_attr(bootstrap, feature(impl_trait_in_assoc_type))]
 
 #[macro_use]
 extern crate rustc_macros;

diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
@@ -197,6 +197,8 @@ declare_features! (
     /// + `impl<I:Iterator> Iterator for &mut Iterator`
     /// + `impl Debug for Foo<'_>`
     (accepted, impl_header_lifetime_elision, "1.31.0", Some(15872)),
+    /// Allows `impl Trait` to be used inside associated types (RFC 2515).
+    (accepted, impl_trait_in_assoc_type, "CURRENT_RUSTC_VERSION", Some(63063)),
     /// Allows referencing `Self` and projections in impl-trait.
     (accepted, impl_trait_projections, "1.74.0", Some(103532)),
     /// Allows using `a..=b` and `..=b` as inclusive range syntaxes.

diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -483,8 +483,6 @@ declare_features! (
     (unstable, half_open_range_patterns_in_slices, "1.66.0", Some(67264)),
     /// Allows `if let` guard in match arms.
     (unstable, if_let_guard, "1.47.0", Some(51114)),
-    /// Allows `impl Trait` to be used inside associated types (RFC 2515).
-    (unstable, impl_trait_in_assoc_type, "1.70.0", Some(63063)),
     /// Allows `impl Trait` as output type in `Fn` traits in return position of functions.
     (unstable, impl_trait_in_fn_trait_return, "1.64.0", Some(99697)),
     /// Allows using imported `main` function

diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
@@ -3,7 +3,7 @@
 #![feature(const_type_name)]
 #![feature(cow_is_borrowed)]
 #![feature(decl_macro)]
-#![feature(impl_trait_in_assoc_type)]
+#![cfg_attr(bootstrap, feature(impl_trait_in_assoc_type))]
 #![feature(inline_const)]
 #![feature(is_sorted)]
 #![feature(let_chains)]

diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
@@ -6,7 +6,7 @@
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
-#![feature(impl_trait_in_assoc_type)]
+#![cfg_attr(bootstrap, feature(impl_trait_in_assoc_type))]
 #![feature(iter_intersperse)]
 #![feature(lazy_cell)]
 #![feature(let_chains)]

diff --git a/tests/rustdoc/auxiliary/issue-73061.rs b/tests/rustdoc/auxiliary/issue-73061.rs
@@ -1,7 +1,5 @@
 //edition:2018
 
-#![feature(impl_trait_in_assoc_type)]
-
 pub trait Foo {
     type X: std::future::Future<Output = ()>;
     fn x(&self) -> Self::X;

diff --git a/tests/ui/associated-types/issue-63591.rs b/tests/ui/associated-types/issue-63591.rs
@@ -1,7 +1,6 @@
 // check-pass
 
 #![feature(associated_type_bounds)]
-#![feature(impl_trait_in_assoc_type)]
 
 fn main() {}
 

diff --git a/tests/ui/coroutine/issue-87142.rs b/tests/ui/coroutine/issue-87142.rs
@@ -4,7 +4,7 @@
 // Regression test for #87142
 // This test needs the above flags and the "lib" crate type.
 
-#![feature(impl_trait_in_assoc_type, coroutine_trait, coroutines)]
+#![feature(coroutine_trait, coroutines)]
 #![crate_type = "lib"]
 
 use std::ops::Coroutine;

diff --git a/tests/ui/feature-gates/feature-gate-impl_trait_in_assoc_type.rs b/tests/ui/feature-gates/feature-gate-impl_trait_in_assoc_type.rs
diff --git a/tests/ui/feature-gates/feature-gate-impl_trait_in_assoc_type.stderr b/tests/ui/feature-gates/feature-gate-impl_trait_in_assoc_type.stderr
diff --git a/tests/ui/generic-associated-types/issue-86218-2.rs b/tests/ui/generic-associated-types/issue-86218-2.rs
@@ -1,7 +1,5 @@
 // check-pass
 
-#![feature(impl_trait_in_assoc_type)]
-
 pub trait Stream {
     type Item;
 }

diff --git a/tests/ui/generic-associated-types/issue-86218.rs b/tests/ui/generic-associated-types/issue-86218.rs
@@ -1,7 +1,5 @@
 // check-pass
 
-#![feature(impl_trait_in_assoc_type)]
-
 pub trait Stream {
     type Item;
 }

diff --git a/tests/ui/generic-associated-types/issue-87258_a.rs b/tests/ui/generic-associated-types/issue-87258_a.rs
@@ -1,5 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
-
 // See https://github.com/rust-lang/rust/issues/87258#issuecomment-883293367
 
 trait Trait1 {}

diff --git a/tests/ui/generic-associated-types/issue-87258_a.stderr b/tests/ui/generic-associated-types/issue-87258_a.stderr
@@ -1,5 +1,5 @@
 error: unconstrained opaque type
-  --> $DIR/issue-87258_a.rs:17:26
+  --> $DIR/issue-87258_a.rs:15:26
    |
 LL |     type FooFuture<'a> = impl Trait1;
    |                          ^^^^^^^^^^^

diff --git a/tests/ui/generic-associated-types/issue-88595.rs b/tests/ui/generic-associated-types/issue-88595.rs
@@ -1,5 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
-
 fn main() {}
 
 #[rustfmt::skip]

diff --git a/tests/ui/generic-associated-types/issue-88595.stderr b/tests/ui/generic-associated-types/issue-88595.stderr
@@ -1,11 +1,11 @@
 error: non-defining opaque type use in defining scope
-  --> $DIR/issue-88595.rs:21:23
+  --> $DIR/issue-88595.rs:19:23
    |
 LL |     fn a(&'a self) -> Self::B<'a> {}
    |                       ^^^^^^^^^^^ generic argument `'a` used twice
    |
 note: for this opaque type
-  --> $DIR/issue-88595.rs:19:18
+  --> $DIR/issue-88595.rs:17:18
    |
 LL |     type B<'b> = impl Clone;
    |                  ^^^^^^^^^^

diff --git a/tests/ui/generic-associated-types/issue-89008.rs b/tests/ui/generic-associated-types/issue-89008.rs
@@ -1,8 +1,6 @@
 // check-pass
 // edition:2021
 
-#![feature(impl_trait_in_assoc_type)]
-
 use std::future::Future;
 use std::marker::PhantomData;
 

diff --git a/tests/ui/generic-associated-types/issue-90014-tait.rs b/tests/ui/generic-associated-types/issue-90014-tait.rs
@@ -4,7 +4,7 @@
 // known-bug: unknown
 // edition:2018
 
-#![feature(impl_trait_in_assoc_type, inherent_associated_types)]
+#![feature(inherent_associated_types)]
 #![allow(incomplete_features)]
 
 use std::future::Future;

diff --git a/tests/ui/generic-associated-types/issue-90014.rs b/tests/ui/generic-associated-types/issue-90014.rs
@@ -1,7 +1,5 @@
 // edition:2018
 
-#![feature(impl_trait_in_assoc_type)]
-
 use std::future::Future;
 
 trait MakeFut {

diff --git a/tests/ui/generic-associated-types/issue-90014.stderr b/tests/ui/generic-associated-types/issue-90014.stderr
@@ -1,5 +1,5 @@
 error[E0477]: the type `&mut ()` does not fulfill the required lifetime
-  --> $DIR/issue-90014.rs:15:20
+  --> $DIR/issue-90014.rs:13:20
    |
 LL |     type Fut<'a>
    |     ------------ definition of `Fut` from trait
@@ -8,7 +8,7 @@ LL |     type Fut<'a> = impl Future<Output = ()>;
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: type must outlive the lifetime `'a` as defined here
-  --> $DIR/issue-90014.rs:15:14
+  --> $DIR/issue-90014.rs:13:14
    |
 LL |     type Fut<'a> = impl Future<Output = ()>;
    |              ^^

diff --git a/tests/ui/impl-trait/associated-impl-trait-type-generic-trait.rs b/tests/ui/impl-trait/associated-impl-trait-type-generic-trait.rs
@@ -1,4 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
 // build-pass (FIXME(62277): could be check-pass?)
 
 trait Bar {}

diff --git a/tests/ui/impl-trait/associated-impl-trait-type-issue-114325.rs b/tests/ui/impl-trait/associated-impl-trait-type-issue-114325.rs
@@ -4,8 +4,6 @@
 // edition: 2021
 // build-pass: ICEd during codegen.
 
-#![feature(impl_trait_in_assoc_type)]
-
 use std::future::Future;
 
 fn main() {

diff --git a/tests/ui/impl-trait/associated-impl-trait-type-trivial.rs b/tests/ui/impl-trait/associated-impl-trait-type-trivial.rs
@@ -1,4 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
 // build-pass (FIXME(62277): could be check-pass?)
 
 trait Bar {}

diff --git a/tests/ui/impl-trait/associated-impl-trait-type.rs b/tests/ui/impl-trait/associated-impl-trait-type.rs
@@ -1,4 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
 // build-pass (FIXME(62277): could be check-pass?)
 
 trait Bar {}

diff --git a/tests/ui/impl-trait/in-assoc-type-unconstrained.rs b/tests/ui/impl-trait/in-assoc-type-unconstrained.rs
@@ -1,5 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
-
 mod compare_ty {
     trait Trait {
         type Ty: IntoIterator<Item = ()>;

diff --git a/tests/ui/impl-trait/in-assoc-type-unconstrained.stderr b/tests/ui/impl-trait/in-assoc-type-unconstrained.stderr
@@ -1,27 +1,27 @@
 error[E0271]: type mismatch resolving `<Option<<() as Trait>::Ty::{opaque#0}> as IntoIterator>::Item == ()`
-  --> $DIR/in-assoc-type-unconstrained.rs:8:19
+  --> $DIR/in-assoc-type-unconstrained.rs:6:19
    |
 LL |         type Ty = Option<impl Sized>;
    |                   ^^^^^^^^^^^^^^^^^^ expected `()`, found opaque type
    |
    = note: expected unit type `()`
             found opaque type `<() as compare_ty::Trait>::Ty::{opaque#0}`
 note: required by a bound in `compare_ty::Trait::Ty`
-  --> $DIR/in-assoc-type-unconstrained.rs:5:31
+  --> $DIR/in-assoc-type-unconstrained.rs:3:31
    |
 LL |         type Ty: IntoIterator<Item = ()>;
    |                               ^^^^^^^^^ required by this bound in `Trait::Ty`
 
 error: unconstrained opaque type
-  --> $DIR/in-assoc-type-unconstrained.rs:8:26
+  --> $DIR/in-assoc-type-unconstrained.rs:6:26
    |
 LL |         type Ty = Option<impl Sized>;
    |                          ^^^^^^^^^^
    |
    = note: `Ty` must be used in combination with a concrete type within the same impl
 
 error[E0053]: method `method` has an incompatible type for trait
-  --> $DIR/in-assoc-type-unconstrained.rs:22:24
+  --> $DIR/in-assoc-type-unconstrained.rs:20:24
    |
 LL |         type Ty = impl Sized;
    |                   ---------- the expected opaque type
@@ -33,20 +33,20 @@ LL |         fn method() -> () {}
    |                        help: change the output type to match the trait: `<() as compare_method::Trait>::Ty`
    |
 note: type in trait
-  --> $DIR/in-assoc-type-unconstrained.rs:17:24
+  --> $DIR/in-assoc-type-unconstrained.rs:15:24
    |
 LL |         fn method() -> Self::Ty;
    |                        ^^^^^^^^
    = note: expected signature `fn() -> <() as compare_method::Trait>::Ty`
               found signature `fn()`
 note: this item must have the opaque type in its signature in order to be able to register hidden types
-  --> $DIR/in-assoc-type-unconstrained.rs:22:12
+  --> $DIR/in-assoc-type-unconstrained.rs:20:12
    |
 LL |         fn method() -> () {}
    |            ^^^^^^
 
 error: unconstrained opaque type
-  --> $DIR/in-assoc-type-unconstrained.rs:20:19
+  --> $DIR/in-assoc-type-unconstrained.rs:18:19
    |
 LL |         type Ty = impl Sized;
    |                   ^^^^^^^^^^

diff --git a/tests/ui/impl-trait/in-assoc-type.rs b/tests/ui/impl-trait/in-assoc-type.rs
@@ -1,8 +1,6 @@
 //! This test checks that we don't allow registering hidden types for
 //! opaque types from other impls.
 
-#![feature(impl_trait_in_assoc_type)]
-
 trait Foo<T> {
     type Bar;
     fn foo(&self) -> <Self as Foo<()>>::Bar

diff --git a/tests/ui/impl-trait/in-assoc-type.stderr b/tests/ui/impl-trait/in-assoc-type.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/in-assoc-type.rs:20:22
+  --> $DIR/in-assoc-type.rs:18:22
    |
 LL |     type Bar = impl std::fmt::Debug;
    |                -------------------- the expected opaque type
@@ -12,7 +12,7 @@ LL |     fn foo(&self) -> <Self as Foo<()>>::Bar {}
    = note: expected opaque type `<() as Foo<()>>::Bar`
                 found unit type `()`
 note: this item must have the opaque type in its signature in order to be able to register hidden types
-  --> $DIR/in-assoc-type.rs:20:8
+  --> $DIR/in-assoc-type.rs:18:8
    |
 LL |     fn foo(&self) -> <Self as Foo<()>>::Bar {}
    |        ^^^

diff --git a/tests/ui/impl-trait/issue-55872-1.rs b/tests/ui/impl-trait/issue-55872-1.rs
@@ -1,5 +1,3 @@
-#![feature(impl_trait_in_assoc_type)]
-
 pub trait Bar {
     type E: Copy;
 

diff --git a/tests/ui/impl-trait/issue-55872-1.stderr b/tests/ui/impl-trait/issue-55872-1.stderr
@@ -1,5 +1,5 @@
 error[E0276]: impl has stricter requirements than trait
-  --> $DIR/issue-55872-1.rs:12:15
+  --> $DIR/issue-55872-1.rs:10:15
    |
 LL |     fn foo<T>() -> Self::E;
    |     ----------------------- definition of `foo` from trait
@@ -8,7 +8,7 @@ LL |     fn foo<T: Default>() -> Self::E {
    |               ^^^^^^^ impl has extra requirement `T: Default`
 
 error[E0277]: the trait bound `S: Copy` is not satisfied in `(S, T)`
-  --> $DIR/issue-55872-1.rs:12:29
+  --> $DIR/issue-55872-1.rs:10:29
    |
 LL |     fn foo<T: Default>() -> Self::E {
    |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `S`, which is required by `(S, T): Copy`
@@ -20,7 +20,7 @@ LL | impl<S: Default + std::marker::Copy> Bar for S {
    |                 +++++++++++++++++++
 
 error[E0277]: the trait bound `T: Copy` is not satisfied in `(S, T)`
-  --> $DIR/issue-55872-1.rs:12:29
+  --> $DIR/issue-55872-1.rs:10:29
    |
 LL |     fn foo<T: Default>() -> Self::E {
    |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `T`, which is required by `(S, T): Copy`

diff --git a/tests/ui/impl-trait/issue-55872-2.rs b/tests/ui/impl-trait/issue-55872-2.rs
@@ -1,7 +1,5 @@
 // edition:2018
 
-#![feature(impl_trait_in_assoc_type)]
-
 pub trait Bar {
     type E: Send;