rust-lang · Voultapher · Jan 23, 2026
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
+#![cfg_attr(all(feature = "nightly", bootstrap), feature(assert_matches))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
-#![cfg_attr(feature = "nightly", feature(assert_matches))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
 #![cfg_attr(feature = "nightly", feature(step_trait))]
 // tidy-alphabetical-end

diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
@@ -2,7 +2,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]

diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
@@ -3,7 +3,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]

diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -5,7 +5,7 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(extern_types)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]

diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]

diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(array_try_map)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]

diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
@@ -10,11 +10,11 @@
 #![allow(internal_features)]
 #![allow(rustc::default_hash_types)]
 #![allow(rustc::potential_query_instability)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![feature(allocator_api)]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
-#![feature(assert_matches)]
 #![feature(auto_traits)]
 #![feature(cfg_select)]
 #![feature(const_default)]

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
@@ -5,7 +5,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
@@ -56,7 +56,7 @@ This API is completely unstable and subject to change.
 */
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(gen_blocks)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]

diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]

diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
@@ -14,7 +14,7 @@
 
 // tidy-alphabetical-start
 #![allow(rustc::direct_use_of_rustc_type_ir)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(extend_one)]
 #![recursion_limit = "512"] // For rustdoc
 // tidy-alphabetical-end

diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
@@ -21,7 +21,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_order_by)]

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
@@ -27,8 +27,8 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(allocator_api)]
-#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_as_ptr)]
 #![feature(box_patterns)]

diff --git a/compiler/rustc_mir_build/src/lib.rs b/compiler/rustc_mir_build/src/lib.rs
@@ -1,7 +1,7 @@
 //! Construction of MIR from HIR.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(try_blocks)]

diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]

diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
@@ -1,5 +1,5 @@
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(const_type_name)]
 #![feature(cow_is_borrowed)]

diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
@@ -1,7 +1,7 @@
 //! The main parser interface.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_query_system/src/lib.rs b/compiler/rustc_query_system/src/lib.rs
@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(core_intrinsics)]
 #![feature(min_specialization)]
 // tidy-alphabetical-end

diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
@@ -8,8 +8,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(arbitrary_self_types)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(const_default)]
 #![feature(const_trait_impl)]

diff --git a/compiler/rustc_symbol_mangling/src/lib.rs b/compiler/rustc_symbol_mangling/src/lib.rs
@@ -88,7 +88,7 @@
 //! DefPaths which are much more robust in the face of changes to the code base.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 // tidy-alphabetical-end
 
 use rustc_hir::def::DefKind;

diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
@@ -11,7 +11,7 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(default_field_values)]

diff --git a/compiler/rustc_ty_utils/src/lib.rs b/compiler/rustc_ty_utils/src/lib.rs
@@ -5,7 +5,7 @@
 //! This API is completely unstable and subject to change.
 
 // tidy-alphabetical-start
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]

diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
@@ -89,7 +89,6 @@
 #![feature(allocator_api)]
 #![feature(array_into_iter_constructors)]
 #![feature(ascii_char)]
-#![feature(assert_matches)]
 #![feature(async_fn_traits)]
 #![feature(async_iterator)]
 #![feature(box_vec_non_null)]

diff --git a/library/alloctests/lib.rs b/library/alloctests/lib.rs
@@ -16,7 +16,6 @@
 // tidy-alphabetical-start
 #![feature(allocator_api)]
 #![feature(array_into_iter_constructors)]
-#![feature(assert_matches)]
 #![feature(box_vec_non_null)]
 #![feature(char_internals)]
 #![feature(const_alloc_error)]

diff --git a/library/alloctests/tests/lib.rs b/library/alloctests/tests/lib.rs
@@ -2,7 +2,6 @@
 #![feature(const_heap)]
 #![feature(deque_extend_front)]
 #![feature(iter_array_chunks)]
-#![feature(assert_matches)]
 #![feature(wtf8_internals)]
 #![feature(cow_is_borrowed)]
 #![feature(core_intrinsics)]

diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
@@ -222,7 +222,7 @@ use prelude::rust_2024::*;
 #[macro_use]
 mod macros;
 
-#[unstable(feature = "assert_matches", issue = "82775")]
+#[stable(feature = "assert_matches", since = "CURRENT_RUSTC_VERSION")]
 pub use crate::macros::{assert_matches, debug_assert_matches};
 
 #[unstable(feature = "derive_from", issue = "144889")]

diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
@@ -147,8 +147,6 @@ macro_rules! assert_ne {
 /// # Examples
 ///
 /// ```
-/// #![feature(assert_matches)]
-///
 /// use std::assert_matches;
 ///
 /// let a = Some(345);
@@ -166,7 +164,7 @@ macro_rules! assert_ne {
 /// assert_matches!(a, Some(x) if x > 100);
 /// // assert_matches!(a, Some(x) if x < 100); // panics
 /// ```
-#[unstable(feature = "assert_matches", issue = "82775")]
+#[stable(feature = "assert_matches", since = "CURRENT_RUSTC_VERSION")]
 #[allow_internal_unstable(panic_internals)]
 #[rustc_macro_transparency = "semiopaque"]
 pub macro assert_matches {
@@ -380,8 +378,6 @@ macro_rules! debug_assert_ne {
 /// # Examples
 ///
 /// ```
-/// #![feature(assert_matches)]
-///
 /// use std::debug_assert_matches;
 ///
 /// let a = Some(345);
@@ -399,7 +395,7 @@ macro_rules! debug_assert_ne {
 /// debug_assert_matches!(a, Some(x) if x > 100);
 /// // debug_assert_matches!(a, Some(x) if x < 100); // panics
 /// ```
-#[unstable(feature = "assert_matches", issue = "82775")]
+#[stable(feature = "assert_matches", since = "CURRENT_RUSTC_VERSION")]
 #[allow_internal_unstable(assert_matches)]
 #[rustc_macro_transparency = "semiopaque"]
 pub macro debug_assert_matches($($arg:tt)*) {

diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
@@ -392,7 +392,6 @@
 //
 // Only for re-exporting:
 // tidy-alphabetical-start
-#![feature(assert_matches)]
 #![feature(async_iterator)]
 #![feature(c_variadic)]
 #![feature(cfg_accessible)]
@@ -722,7 +721,7 @@ pub use core::{
     assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, r#try, unimplemented,
     unreachable, write, writeln,
 };
-#[unstable(feature = "assert_matches", issue = "82775")]
+#[stable(feature = "assert_matches", since = "CURRENT_RUSTC_VERSION")]
 pub use core::{assert_matches, debug_assert_matches};
 
 // Re-export unstable derive macro defined through core.

diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
@@ -1,11 +1,11 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/",
     html_playground_url = "https://play.rust-lang.org/"
 )]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
-#![feature(assert_matches)]
 #![feature(box_into_inner)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]

diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -3,7 +3,7 @@
 #![feature(macro_metavar_expr)]
 #![feature(never_type)]
 #![feature(rustc_private)]
-#![feature(assert_matches)]
+#![cfg_attr(bootstrap, feature(assert_matches))]
 #![feature(unwrap_infallible)]
 #![recursion_limit = "512"]
 #![allow(

diff --git a/tests/ui-fulldeps/rustc_public/check_abi.rs b/tests/ui-fulldeps/rustc_public/check_abi.rs
@@ -6,7 +6,6 @@
 //@ ignore-remote
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 #![feature(ascii_char, ascii_char_variants)]
 
 extern crate rustc_driver;

diff --git a/tests/ui-fulldeps/rustc_public/check_allocation.rs b/tests/ui-fulldeps/rustc_public/check_allocation.rs
@@ -8,7 +8,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 #![feature(ascii_char, ascii_char_variants)]
 
 extern crate rustc_hir;

diff --git a/tests/ui-fulldeps/rustc_public/check_assoc_items.rs b/tests/ui-fulldeps/rustc_public/check_assoc_items.rs
@@ -8,7 +8,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_coroutine_body.rs b/tests/ui-fulldeps/rustc_public/check_coroutine_body.rs
@@ -7,7 +7,6 @@
 //@ edition: 2024
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_crate_defs.rs b/tests/ui-fulldeps/rustc_public/check_crate_defs.rs
@@ -6,7 +6,6 @@
 //@ ignore-remote
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_hir;
 extern crate rustc_middle;

diff --git a/tests/ui-fulldeps/rustc_public/check_def_ty.rs b/tests/ui-fulldeps/rustc_public/check_def_ty.rs
@@ -8,7 +8,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_defs.rs b/tests/ui-fulldeps/rustc_public/check_defs.rs
@@ -7,7 +7,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_foreign.rs b/tests/ui-fulldeps/rustc_public/check_foreign.rs
@@ -7,7 +7,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_instance.rs b/tests/ui-fulldeps/rustc_public/check_instance.rs
@@ -7,7 +7,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_intrinsics.rs b/tests/ui-fulldeps/rustc_public/check_intrinsics.rs
@@ -10,7 +10,6 @@
 //@ ignore-remote
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 extern crate rustc_hir;

diff --git a/tests/ui-fulldeps/rustc_public/check_item_kind.rs b/tests/ui-fulldeps/rustc_public/check_item_kind.rs
@@ -7,7 +7,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;
 

diff --git a/tests/ui-fulldeps/rustc_public/check_trait_queries.rs b/tests/ui-fulldeps/rustc_public/check_trait_queries.rs
@@ -7,7 +7,6 @@
 //@ edition: 2021
 
 #![feature(rustc_private)]
-#![feature(assert_matches)]
 
 extern crate rustc_middle;