rust-lang · bors · May 26, 2024 · Feb 21, 2024
diff --git a/compiler/rustc_const_eval/src/check_consts/ops.rs b/compiler/rustc_const_eval/src/check_consts/ops.rs
@@ -309,7 +309,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
         }
 
         if let ConstContext::Static(_) = ccx.const_kind() {
-            err.note("consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell");
+            err.note("consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`");
         }
 
         err

diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
@@ -24,7 +24,6 @@
 #![feature(extend_one)]
 #![feature(hash_raw_entry)]
 #![feature(hasher_prefixfree_extras)]
-#![feature(lazy_cell)]
 #![feature(lint_reasons)]
 #![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]

diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
@@ -1,6 +1,5 @@
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![feature(lazy_cell)]
 #![feature(rustc_attrs)]
 #![feature(type_alias_impl_trait)]
 #![allow(internal_features)]

diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs
@@ -14,7 +14,6 @@
 #![allow(internal_features)]
 #![feature(rustdoc_internals)]
 #![doc(rust_logo)]
-#![feature(lazy_cell)]
 
 mod accepted;
 mod builtin_attrs;

diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
@@ -68,7 +68,6 @@ This API is completely unstable and subject to change.
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(never_type)]
-#![feature(lazy_cell)]
 #![feature(slice_partition_dedup)]
 #![feature(try_blocks)]
 

diff --git a/compiler/rustc_interface/src/lib.rs b/compiler/rustc_interface/src/lib.rs
@@ -1,5 +1,4 @@
 #![feature(decl_macro)]
-#![feature(lazy_cell)]
 #![feature(let_chains)]
 #![feature(thread_spawn_unchecked)]
 #![feature(try_blocks)]

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
@@ -1316,10 +1316,8 @@ declare_lint! {
     /// * If you are trying to perform a one-time initialization of a global:
     ///     * If the value can be computed at compile-time, consider using
     ///       const-compatible values (see [Constant Evaluation]).
-    ///     * For more complex single-initialization cases, consider using a
-    ///       third-party crate, such as [`lazy_static`] or [`once_cell`].
-    ///     * If you are using the [nightly channel], consider the new
-    ///       [`lazy`] module in the standard library.
+    ///     * For more complex single-initialization cases, consider using
+    ///       [`std::sync::LazyLock`].
     /// * If you truly need a mutable global, consider using a [`static`],
     ///   which has a variety of options:
     ///   * Simple data types can be directly defined and mutated with an
@@ -1334,9 +1332,7 @@ declare_lint! {
     /// [Constant Evaluation]: https://doc.rust-lang.org/reference/const_eval.html
     /// [`static`]: https://doc.rust-lang.org/reference/items/static-items.html
     /// [mutable `static`]: https://doc.rust-lang.org/reference/items/static-items.html#mutable-statics
-    /// [`lazy`]: https://doc.rust-lang.org/nightly/std/lazy/index.html
-    /// [`lazy_static`]: https://crates.io/crates/lazy_static
-    /// [`once_cell`]: https://crates.io/crates/once_cell
+    /// [`std::sync::LazyLock`]: https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html
     /// [`atomic`]: https://doc.rust-lang.org/std/sync/atomic/index.html
     /// [`Mutex`]: https://doc.rust-lang.org/std/sync/struct.Mutex.html
     pub CONST_ITEM_MUTATION,

diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
@@ -1,5 +1,4 @@
 #![feature(let_chains)]
-#![feature(lazy_cell)]
 #![feature(option_get_or_insert_default)]
 #![feature(rustc_attrs)]
 #![feature(map_many_mut)]

diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
@@ -245,7 +245,7 @@ use crate::ptr::{self, NonNull};
 mod lazy;
 mod once;
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 pub use lazy::LazyCell;
 #[stable(feature = "once_cell", since = "1.70.0")]
 pub use once::OnceCell;

diff --git a/library/core/src/cell/lazy.rs b/library/core/src/cell/lazy.rs
@@ -18,8 +18,6 @@ enum State<T, F> {
 /// # Examples
 ///
 /// ```
-/// #![feature(lazy_cell)]
-///
 /// use std::cell::LazyCell;
 ///
 /// let lazy: LazyCell<i32> = LazyCell::new(|| {
@@ -36,7 +34,7 @@ enum State<T, F> {
 /// //   92
 /// //   92
 /// ```
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 pub struct LazyCell<T, F = fn() -> T> {
     state: UnsafeCell<State<T, F>>,
 }
@@ -47,8 +45,6 @@ impl<T, F: FnOnce() -> T> LazyCell<T, F> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(lazy_cell)]
-    ///
     /// use std::cell::LazyCell;
     ///
     /// let hello = "Hello, World!".to_string();
@@ -58,7 +54,8 @@ impl<T, F: FnOnce() -> T> LazyCell<T, F> {
     /// assert_eq!(&*lazy, "HELLO, WORLD!");
     /// ```
     #[inline]
-    #[unstable(feature = "lazy_cell", issue = "109736")]
+    #[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
     pub const fn new(f: F) -> LazyCell<T, F> {
         LazyCell { state: UnsafeCell::new(State::Uninit(f)) }
     }
@@ -70,7 +67,6 @@ impl<T, F: FnOnce() -> T> LazyCell<T, F> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(lazy_cell)]
     /// #![feature(lazy_cell_consume)]
     ///
     /// use std::cell::LazyCell;
@@ -99,8 +95,6 @@ impl<T, F: FnOnce() -> T> LazyCell<T, F> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(lazy_cell)]
-    ///
     /// use std::cell::LazyCell;
     ///
     /// let lazy = LazyCell::new(|| 92);
@@ -109,7 +103,7 @@ impl<T, F: FnOnce() -> T> LazyCell<T, F> {
     /// assert_eq!(&*lazy, &92);
     /// ```
     #[inline]
-    #[unstable(feature = "lazy_cell", issue = "109736")]
+    #[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
     pub fn force(this: &LazyCell<T, F>) -> &T {
         // SAFETY:
         // This invalidates any mutable references to the data. The resulting
@@ -173,7 +167,7 @@ impl<T, F> LazyCell<T, F> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T, F: FnOnce() -> T> Deref for LazyCell<T, F> {
     type Target = T;
     #[inline]
@@ -182,7 +176,7 @@ impl<T, F: FnOnce() -> T> Deref for LazyCell<T, F> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: Default> Default for LazyCell<T> {
     /// Creates a new lazy value using `Default` as the initializing function.
     #[inline]
@@ -191,7 +185,7 @@ impl<T: Default> Default for LazyCell<T> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: fmt::Debug, F> fmt::Debug for LazyCell<T, F> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut d = f.debug_tuple("LazyCell");

diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
@@ -96,7 +96,6 @@
 #![feature(pointer_is_aligned_to)]
 #![feature(portable_simd)]
 #![feature(ptr_metadata)]
-#![feature(lazy_cell)]
 #![feature(unsized_tuple_coercion)]
 #![feature(const_option)]
 #![feature(const_option_ext)]

diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
@@ -395,7 +395,6 @@
 #![feature(edition_panic)]
 #![feature(format_args_nl)]
 #![feature(get_many_mut)]
-#![feature(lazy_cell)]
 #![feature(log_syntax)]
 #![feature(test)]
 #![feature(trace_macros)]

diff --git a/library/std/src/sync/lazy_lock.rs b/library/std/src/sync/lazy_lock.rs
@@ -31,8 +31,6 @@ union Data<T, F> {
 /// Initialize static variables with `LazyLock`.
 ///
 /// ```
-/// #![feature(lazy_cell)]
-///
 /// use std::collections::HashMap;
 ///
 /// use std::sync::LazyLock;
@@ -61,8 +59,6 @@ union Data<T, F> {
 /// ```
 /// Initialize fields with `LazyLock`.
 /// ```
-/// #![feature(lazy_cell)]
-///
 /// use std::sync::LazyLock;
 ///
 /// #[derive(Debug)]
@@ -76,17 +72,29 @@ union Data<T, F> {
 ///     println!("{}", *data.number);
 /// }
 /// ```
-
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 pub struct LazyLock<T, F = fn() -> T> {
     once: Once,
     data: UnsafeCell<Data<T, F>>,
 }
 
 impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// Creates a new lazy value with the given initializing function.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::sync::LazyLock;
+    ///
+    /// let hello = "Hello, World!".to_string();
+    ///
+    /// let lazy = LazyLock::new(|| hello.to_uppercase());
+    ///
+    /// assert_eq!(&*lazy, "HELLO, WORLD!");
+    /// ```
     #[inline]
-    #[unstable(feature = "lazy_cell", issue = "109736")]
+    #[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
     pub const fn new(f: F) -> LazyLock<T, F> {
         LazyLock { once: Once::new(), data: UnsafeCell::new(Data { f: ManuallyDrop::new(f) }) }
     }
@@ -107,7 +115,6 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(lazy_cell)]
     /// #![feature(lazy_cell_consume)]
     ///
     /// use std::sync::LazyLock;
@@ -145,8 +152,6 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(lazy_cell)]
-    ///
     /// use std::sync::LazyLock;
     ///
     /// let lazy = LazyLock::new(|| 92);
@@ -155,7 +160,7 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// assert_eq!(&*lazy, &92);
     /// ```
     #[inline]
-    #[unstable(feature = "lazy_cell", issue = "109736")]
+    #[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
     pub fn force(this: &LazyLock<T, F>) -> &T {
         this.once.call_once(|| {
             // SAFETY: `call_once` only runs this closure once, ever.
@@ -191,7 +196,7 @@ impl<T, F> LazyLock<T, F> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T, F> Drop for LazyLock<T, F> {
     fn drop(&mut self) {
         match self.once.state() {
@@ -204,7 +209,7 @@ impl<T, F> Drop for LazyLock<T, F> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T, F: FnOnce() -> T> Deref for LazyLock<T, F> {
     type Target = T;
 
@@ -219,7 +224,7 @@ impl<T, F: FnOnce() -> T> Deref for LazyLock<T, F> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: Default> Default for LazyLock<T> {
     /// Creates a new lazy value using `Default` as the initializing function.
     #[inline]
@@ -228,7 +233,7 @@ impl<T: Default> Default for LazyLock<T> {
     }
 }
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: fmt::Debug, F> fmt::Debug for LazyLock<T, F> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut d = f.debug_tuple("LazyLock");
@@ -242,13 +247,13 @@ impl<T: fmt::Debug, F> fmt::Debug for LazyLock<T, F> {
 
 // We never create a `&F` from a `&LazyLock<T, F>` so it is fine
 // to not impl `Sync` for `F`.
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 unsafe impl<T: Sync + Send, F: Send> Sync for LazyLock<T, F> {}
 // auto-derived `Send` impl is OK.
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: RefUnwindSafe + UnwindSafe, F: UnwindSafe> RefUnwindSafe for LazyLock<T, F> {}
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 impl<T: UnwindSafe, F: UnwindSafe> UnwindSafe for LazyLock<T, F> {}
 
 #[cfg(test)]

diff --git a/library/std/src/sync/mod.rs b/library/std/src/sync/mod.rs
@@ -179,7 +179,7 @@ pub use self::rwlock::{MappedRwLockReadGuard, MappedRwLockWriteGuard};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard};
 
-#[unstable(feature = "lazy_cell", issue = "109736")]
+#[stable(feature = "lazy_cell", since = "CURRENT_RUSTC_VERSION")]
 pub use self::lazy_lock::LazyLock;
 #[stable(feature = "once_cell", since = "1.70.0")]
 pub use self::once_lock::OnceLock;

diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
@@ -8,7 +8,6 @@
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]
-#![feature(lazy_cell)]
 #![feature(let_chains)]
 #![feature(never_type)]
 #![feature(round_char_boundary)]

diff --git a/src/tools/clippy/clippy_dev/src/lib.rs b/src/tools/clippy/clippy_dev/src/lib.rs
@@ -1,4 +1,3 @@
-#![feature(lazy_cell)]
 #![feature(let_chains)]
 #![feature(rustc_private)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]

diff --git a/src/tools/clippy/src/driver.rs b/src/tools/clippy/src/driver.rs
@@ -2,7 +2,6 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(rustc_private)]
 #![feature(let_chains)]
-#![feature(lazy_cell)]
 #![feature(lint_reasons)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 // warn on lints, that are included in `rust-lang/rust`s bootstrap

diff --git a/src/tools/clippy/tests/compile-test.rs b/src/tools/clippy/tests/compile-test.rs
@@ -1,4 +1,3 @@
-#![feature(lazy_cell)]
 #![feature(is_sorted)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 #![warn(rust_2018_idioms, unused_lifetimes)]

diff --git a/src/tools/clippy/tests/dogfood.rs b/src/tools/clippy/tests/dogfood.rs
@@ -3,7 +3,6 @@
 //!
 //! See [Eating your own dog food](https://en.wikipedia.org/wiki/Eating_your_own_dog_food) for context
 
-#![feature(lazy_cell)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 #![warn(rust_2018_idioms, unused_lifetimes)]
 

diff --git a/src/tools/clippy/tests/lint_message_convention.rs b/src/tools/clippy/tests/lint_message_convention.rs
@@ -1,4 +1,3 @@
-#![feature(lazy_cell)]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 #![warn(rust_2018_idioms, unused_lifetimes)]
 

diff --git a/src/tools/clippy/tests/workspace.rs b/src/tools/clippy/tests/workspace.rs
@@ -1,5 +1,3 @@
-#![feature(lazy_cell)]
-
 use std::path::PathBuf;
 use std::process::Command;
 use test_utils::{CARGO_CLIPPY_PATH, IS_RUSTC_TEST_SUITE};

diff --git a/tests/ui/borrowck/issue-64453.stderr b/tests/ui/borrowck/issue-64453.stderr
@@ -14,7 +14,7 @@ LL | static settings_dir: String = format!("");
    |                               ^^^^^^^^^^^
    |
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
-   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`
    = note: this error originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0507]: cannot move out of static item `settings_dir`

diff --git a/tests/ui/consts/issue-16538.stderr b/tests/ui/consts/issue-16538.stderr
@@ -5,7 +5,7 @@ LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
-   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`
 
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
   --> $DIR/issue-16538.rs:11:22