Use assert_matches around the compiler

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -3,6 +3,8 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 
+use std::assert_matches::assert_matches;
+
 use rustc_errors::{Applicability, Diag};
 use rustc_hir as hir;
 use rustc_hir::intravisit::Visitor;
@@ -116,7 +118,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     // path_span must be `Some` as otherwise the if condition is true
                     let path_span = path_span.unwrap();
                     // path_span is only present in the case of closure capture
-                    assert!(matches!(later_use_kind, LaterUseKind::ClosureCapture));
+                    assert_matches!(later_use_kind, LaterUseKind::ClosureCapture);
                     if !borrow_span.is_some_and(|sp| sp.overlaps(var_or_use_span)) {
                         let path_label = "used here by closure";
                         let capture_kind_label = message;
@@ -147,7 +149,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     // path_span must be `Some` as otherwise the if condition is true
                     let path_span = path_span.unwrap();
                     // path_span is only present in the case of closure capture
-                    assert!(matches!(later_use_kind, LaterUseKind::ClosureCapture));
+                    assert_matches!(later_use_kind, LaterUseKind::ClosureCapture);
                     if borrow_span.map(|sp| !sp.overlaps(var_or_use_span)).unwrap_or(true) {
                         let path_label = "used here by closure";
                         let capture_kind_label = message;

compiler/rustc_codegen_llvm/src/asm.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use libc::{c_char, c_uint};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_codegen_ssa::mir::operand::OperandValue;
@@ -89,7 +91,7 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                         // if the target feature needed by the register class is
                         // disabled. This is necessary otherwise LLVM will try
                         // to actually allocate a register for the dummy output.
-                        assert!(matches!(reg, InlineAsmRegOrRegClass::Reg(_)));
+                        assert_matches!(reg, InlineAsmRegOrRegClass::Reg(_));
                         clobbers.push(format!("~{}", reg_to_llvm(reg, None)));
                         continue;
                     } else {

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::cmp::Ordering;
 
 use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh, wants_wasm_eh};
@@ -1142,7 +1143,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
     if cfg!(debug_assertions) {
         for (ty, arg) in arg_tys.iter().zip(args) {
             if ty.is_simd() {
-                assert!(matches!(arg.val, OperandValue::Immediate(_)));
+                assert_matches!(arg.val, OperandValue::Immediate(_));
             }
         }
     }

compiler/rustc_codegen_llvm/src/lib.rs

@@ -8,6 +8,7 @@
 #![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(hash_raw_entry)]

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -1,4 +1,5 @@
 use std::any::Any;
+use std::assert_matches::assert_matches;
 use std::marker::PhantomData;
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::{channel, Receiver, Sender};
@@ -1963,7 +1964,7 @@ impl SharedEmitterMain {
                     sess.dcx().abort_if_errors();
                 }
                 Ok(SharedEmitterMessage::InlineAsmError(cookie, msg, level, source)) => {
-                    assert!(matches!(level, Level::Error | Level::Warning | Level::Note));
+                    assert_matches!(level, Level::Error | Level::Warning | Level::Note);
                     let msg = msg.strip_prefix("error: ").unwrap_or(&msg).to_string();
                     let mut err = Diag::<()>::new(sess.dcx(), level, msg);
 

compiler/rustc_codegen_ssa/src/lib.rs

@@ -4,6 +4,7 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::fmt;
 
 use arrayvec::ArrayVec;
@@ -389,7 +390,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
             }
             // Newtype vector of array, e.g. #[repr(simd)] struct S([i32; 4]);
             (OperandValue::Immediate(llval), Abi::Aggregate { sized: true }) => {
-                assert!(matches!(self.layout.abi, Abi::Vector { .. }));
+                assert_matches!(self.layout.abi, Abi::Vector { .. });
 
                 let llfield_ty = bx.cx().backend_type(field);
 

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use arrayvec::ArrayVec;
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
@@ -220,7 +222,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         match operand.val {
             OperandValue::Ref(source_place_val) => {
                 assert_eq!(source_place_val.llextra, None);
-                assert!(matches!(operand_kind, OperandValueKind::Ref));
+                assert_matches!(operand_kind, OperandValueKind::Ref);
                 Some(bx.load_operand(source_place_val.with_type(cast)).val)
             }
             OperandValue::ZeroSized => {

compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::ty::layout::{HasParamEnv, TyAndLayout};
 use rustc_middle::ty::{Instance, Ty};
@@ -254,10 +256,10 @@ pub trait BuilderMethods<'a, 'tcx>:
         } else {
             (in_ty, dest_ty)
         };
-        assert!(matches!(
+        assert_matches!(
             self.cx().type_kind(float_ty),
             TypeKind::Half | TypeKind::Float | TypeKind::Double | TypeKind::FP128
-        ));
+        );
         assert_eq!(self.cx().type_kind(int_ty), TypeKind::Integer);
 
         if let Some(false) = self.cx().sess().opts.unstable_opts.saturating_float_casts {

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -1,5 +1,6 @@
 //! The `Visitor` responsible for actually checking a `mir::Body` for invalid operations.
 
+use std::assert_matches::assert_matches;
 use std::mem;
 use std::ops::Deref;
 
@@ -590,7 +591,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 if is_int_bool_or_char(lhs_ty) && is_int_bool_or_char(rhs_ty) {
                     // Int, bool, and char operations are fine.
                 } else if lhs_ty.is_fn_ptr() || lhs_ty.is_unsafe_ptr() {
-                    assert!(matches!(
+                    assert_matches!(
                         op,
                         BinOp::Eq
                             | BinOp::Ne
@@ -599,7 +600,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                             | BinOp::Ge
                             | BinOp::Gt
                             | BinOp::Offset
-                    ));
+                    );
 
                     self.check_op(ops::RawPtrComparison);
                 } else if lhs_ty.is_floating_point() || rhs_ty.is_floating_point() {

compiler/rustc_const_eval/src/interpret/call.rs

@@ -1,5 +1,6 @@
 //! Manages calling a concrete function (with known MIR body) with argument passing,
 //! and returning the return value to the caller.
+use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 
 use either::{Left, Right};
@@ -557,7 +558,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     unwind,
                 )? {
                     assert!(!self.tcx.intrinsic(fallback.def_id()).unwrap().must_be_overridden);
-                    assert!(matches!(fallback.def, ty::InstanceKind::Item(_)));
+                    assert_matches!(fallback.def, ty::InstanceKind::Item(_));
                     return self.init_fn_call(
                         FnVal::Instance(fallback),
                         (caller_abi, caller_fn_abi),

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -2,6 +2,8 @@
 //! looking at their MIR. Intrinsics/functions supported here are shared by CTFE
 //! and miri.
 
+use std::assert_matches::assert_matches;
+
 use rustc_hir::def_id::DefId;
 use rustc_middle::mir::{self, BinOp, ConstValue, NonDivergingIntrinsic};
 use rustc_middle::ty::layout::{LayoutOf as _, TyAndLayout, ValidityRequirement};
@@ -510,7 +512,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         dest: &MPlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         assert_eq!(a.layout.ty, b.layout.ty);
-        assert!(matches!(a.layout.ty.kind(), ty::Int(..) | ty::Uint(..)));
+        assert_matches!(a.layout.ty.kind(), ty::Int(..) | ty::Uint(..));
 
         // Performs an exact division, resulting in undefined behavior where
         // `x % y != 0` or `y == 0` or `x == T::MIN && y == -1`.
@@ -536,8 +538,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         r: &ImmTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx, Scalar<M::Provenance>> {
         assert_eq!(l.layout.ty, r.layout.ty);
-        assert!(matches!(l.layout.ty.kind(), ty::Int(..) | ty::Uint(..)));
+        assert_matches!(l.layout.ty.kind(), ty::Int(..) | ty::Uint(..));
-        assert!(matches!(mir_op, BinOp::Add | BinOp::Sub));
+        assert_matches!(mir_op, BinOp::Add | BinOp::Sub);
 
         let (val, overflowed) =
             self.binary_op(mir_op.wrapping_to_overflowing().unwrap(), l, r)?.to_scalar_pair();

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -342,7 +342,7 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
             }
             // extract fields from types with `ScalarPair` ABI
             (Immediate::ScalarPair(a_val, b_val), Abi::ScalarPair(a, b)) => {
-                assert!(matches!(layout.abi, Abi::Scalar(..)));
+                assert_matches!(layout.abi, Abi::Scalar(..));
                 Immediate::from(if offset.bytes() == 0 {
                     debug_assert_eq!(layout.size, a.size(cx));
                     a_val

compiler/rustc_data_structures/src/graph/scc/mod.rs

@@ -8,6 +8,7 @@
 //! Typical examples would include: minimum element in SCC, maximum element
 //! reachable from it, etc.
 
+use std::assert_matches::debug_assert_matches;
 use std::fmt::Debug;
 use std::ops::Range;
 
@@ -569,7 +570,7 @@ where
                     // This None marks that we still have the initialize this node's frame.
                     debug!(?depth, ?node);
 
-                    debug_assert!(matches!(self.node_states[node], NodeState::NotVisited));
+                    debug_assert_matches!(self.node_states[node], NodeState::NotVisited);
 
                     // Push `node` onto the stack.
                     self.node_states[node] = NodeState::BeingVisited {

compiler/rustc_data_structures/src/lib.rs

@@ -18,6 +18,7 @@
 #![feature(array_windows)]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
+#![feature(assert_matches)]
 #![feature(auto_traits)]
 #![feature(cfg_match)]
 #![feature(core_intrinsics)]

compiler/rustc_errors/src/lib.rs

@@ -10,6 +10,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_into_inner)]
 #![feature(box_patterns)]
@@ -28,6 +29,7 @@
 
 extern crate self as rustc_errors;
 
+use std::assert_matches::assert_matches;
 use std::backtrace::{Backtrace, BacktraceStatus};
 use std::borrow::Cow;
 use std::cell::Cell;
@@ -1490,7 +1492,7 @@ impl DiagCtxtInner {
             // Future breakages aren't emitted if they're `Level::Allow` or
             // `Level::Expect`, but they still need to be constructed and
             // stashed below, so they'll trigger the must_produce_diag check.
-            assert!(matches!(diagnostic.level, Error | Warning | Allow | Expect(_)));
+            assert_matches!(diagnostic.level, Error | Warning | Allow | Expect(_));
             self.future_breakage_diagnostics.push(diagnostic.clone());
         }
 

compiler/rustc_hir_analysis/src/check/intrinsicck.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::debug_assert_matches;
+
 use rustc_ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir::{self as hir, LangItem};
@@ -457,17 +459,17 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
                 }
                 // Typeck has checked that Const operands are integers.
                 hir::InlineAsmOperand::Const { anon_const } => {
-                    debug_assert!(matches!(
+                    debug_assert_matches!(
                         self.tcx.type_of(anon_const.def_id).instantiate_identity().kind(),
                         ty::Error(_) | ty::Int(_) | ty::Uint(_)
-                    ));
+                    );
                 }
                 // Typeck has checked that SymFn refers to a function.
                 hir::InlineAsmOperand::SymFn { anon_const } => {
-                    debug_assert!(matches!(
+                    debug_assert_matches!(
                         self.tcx.type_of(anon_const.def_id).instantiate_identity().kind(),
                         ty::Error(_) | ty::FnDef(..)
-                    ));
+                    );
                 }
                 // AST lowering guarantees that SymStatic points to a static.
                 hir::InlineAsmOperand::SymStatic { .. } => {}

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -1,6 +1,7 @@
 //! Check properties that are required by built-in traits and set
 //! up data structures required by type-checking/codegen.
 
+use std::assert_matches::assert_matches;
 use std::collections::BTreeMap;
 
 use rustc_data_structures::fx::FxHashSet;
@@ -129,7 +130,7 @@ fn visit_implementation_of_const_param_ty(
     checker: &Checker<'_>,
     kind: LangItem,
 ) -> Result<(), ErrorGuaranteed> {
-    assert!(matches!(kind, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy));
+    assert_matches!(kind, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy);
 
     let tcx = checker.tcx;
     let header = checker.impl_header;

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::ops::ControlFlow;
 
 use hir::intravisit::{self, Visitor};
@@ -207,9 +208,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 ..
             }) => {
                 if in_trait {
-                    assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn))
+                    assert_matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn);
                 } else {
-                    assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn))
+                    assert_matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn);
                 }
                 Some(fn_def_id.to_def_id())
             }
@@ -218,9 +219,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 ..
             }) => {
                 if in_assoc_ty {
-                    assert!(matches!(tcx.def_kind(parent), DefKind::AssocTy));
+                    assert_matches!(tcx.def_kind(parent), DefKind::AssocTy);
                 } else {
-                    assert!(matches!(tcx.def_kind(parent), DefKind::TyAlias));
+                    assert_matches!(tcx.def_kind(parent), DefKind::TyAlias);
                 }
                 debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent);
                 // Opaque types are always nested within another item, and

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use hir::{HirId, Node};
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
@@ -601,7 +603,7 @@ pub(super) fn implied_predicates_with_filter(
     let Some(trait_def_id) = trait_def_id.as_local() else {
         // if `assoc_name` is None, then the query should've been redirected to an
         // external provider
-        assert!(matches!(filter, PredicateFilter::SelfThatDefines(_)));
+        assert_matches!(filter, PredicateFilter::SelfThatDefines(_));
         return tcx.explicit_super_predicates_of(trait_def_id);
     };
 

compiler/rustc_hir_analysis/src/delegation.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::debug_assert_matches;
+
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -63,7 +65,7 @@ enum FnKind {
 }
 
 fn fn_kind<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> FnKind {
-    debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn));
+    debug_assert_matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn);
 
     let parent = tcx.parent(def_id);
     match tcx.def_kind(parent) {

compiler/rustc_hir_analysis/src/impl_wf_check.rs

@@ -8,6 +8,8 @@
 //! specialization errors. These things can (and probably should) be
 //! fixed, but for the moment it's easier to do these checks early.
 
+use std::assert_matches::debug_assert_matches;
+
 use min_specialization::check_min_specialization;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::codes::*;
@@ -54,7 +56,7 @@ mod min_specialization;
 pub fn check_impl_wf(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
     let min_specialization = tcx.features().min_specialization;
     let mut res = Ok(());
-    debug_assert!(matches!(tcx.def_kind(impl_def_id), DefKind::Impl { .. }));
+    debug_assert_matches!(tcx.def_kind(impl_def_id), DefKind::Impl { .. });
     res = res.and(enforce_impl_params_are_constrained(tcx, impl_def_id));
     if min_specialization {
         res = res.and(check_min_specialization(tcx, impl_def_id));

compiler/rustc_hir_analysis/src/lib.rs

@@ -62,6 +62,7 @@ This API is completely unstable and subject to change.
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(control_flow_enum)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]

compiler/rustc_infer/src/infer/outlives/verify.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_middle::ty::{self, OutlivesPredicate, Ty, TyCtxt};
 use rustc_type_ir::outlives::{compute_alias_components_recursive, Component};
 use smallvec::smallvec;
@@ -181,7 +183,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         &self,
         generic_ty: Ty<'tcx>,
     ) -> Vec<ty::PolyTypeOutlivesPredicate<'tcx>> {
-        assert!(matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_)));
+        assert_matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_));
         self.declared_generic_bounds_from_env_for_erased_ty(generic_ty)
     }
 

compiler/rustc_infer/src/lib.rs

@@ -18,6 +18,7 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]

compiler/rustc_middle/src/ty/consts/kind.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_macros::{extension, HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 
 use super::Const;
@@ -80,7 +82,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn binop_args(self) -> (Ty<'tcx>, Ty<'tcx>, Const<'tcx>, Const<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::Binop(_)));
+        assert_matches!(self.kind, ExprKind::Binop(_));
 
         match self.args().as_slice() {
             [lhs_ty, rhs_ty, lhs_ct, rhs_ct] => (
@@ -101,7 +103,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn unop_args(self) -> (Ty<'tcx>, Const<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::UnOp(_)));
+        assert_matches!(self.kind, ExprKind::UnOp(_));
 
         match self.args().as_slice() {
             [ty, ct] => (ty.expect_ty(), ct.expect_const()),
@@ -125,7 +127,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn call_args(self) -> (Ty<'tcx>, Const<'tcx>, impl Iterator<Item = Const<'tcx>>) {
-        assert!(matches!(self.kind, ExprKind::FunctionCall));
+        assert_matches!(self.kind, ExprKind::FunctionCall);
 
         match self.args().as_slice() {
             [func_ty, func, rest @ ..] => (
@@ -152,7 +154,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn cast_args(self) -> (Ty<'tcx>, Const<'tcx>, Ty<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::Cast(_)));
+        assert_matches!(self.kind, ExprKind::Cast(_));
 
         match self.args().as_slice() {
             [value_ty, value, to_ty] => {

compiler/rustc_mir_dataflow/src/impls/initialized.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_index::bit_set::{BitSet, ChunkedBitSet};
 use rustc_index::Idx;
 use rustc_middle::bug;
@@ -496,7 +498,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, '_, 'tcx> {
         });
         if self.skip_unreachable_unwind.contains(location.block) {
             let mir::TerminatorKind::Drop { target, unwind, .. } = terminator.kind else { bug!() };
-            assert!(matches!(unwind, mir::UnwindAction::Cleanup(_)));
+            assert_matches!(unwind, mir::UnwindAction::Cleanup(_));
             TerminatorEdges::Single(target)
         } else {
             terminator.edges()

compiler/rustc_mir_dataflow/src/lib.rs

@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]

compiler/rustc_mir_dataflow/src/value_analysis.rs

@@ -32,6 +32,7 @@
 //! Because of that, we can assume that the only way to change the value behind a tracked place is
 //! by direct assignment.
 
+use std::assert_matches::assert_matches;
 use std::fmt::{Debug, Formatter};
 use std::ops::Range;
 
@@ -54,7 +55,7 @@ use crate::{Analysis, AnalysisDomain, JoinSemiLattice, SwitchIntEdgeEffects};
 
 pub trait ValueAnalysis<'tcx> {
     /// For each place of interest, the analysis tracks a value of the given type.
-    type Value: Clone + JoinSemiLattice + HasBottom + HasTop;
+    type Value: Clone + JoinSemiLattice + HasBottom + HasTop + Debug;
 
     const NAME: &'static str;
 
@@ -344,7 +345,7 @@ impl<'tcx, T: ValueAnalysis<'tcx>> AnalysisDomain<'tcx> for ValueAnalysisWrapper
 
     fn initialize_start_block(&self, body: &Body<'tcx>, state: &mut Self::Domain) {
         // The initial state maps all tracked places of argument projections to ⊤ and the rest to ⊥.
-        assert!(matches!(state, State::Unreachable));
+        assert_matches!(state, State::Unreachable);
         *state = State::new_reachable();
         for arg in body.args_iter() {
             state.flood(PlaceRef { local: arg, projection: &[] }, self.0.map());

compiler/rustc_mir_transform/src/promote_consts.rs

@@ -468,7 +468,7 @@ impl<'tcx> Validator<'_, 'tcx> {
 
                 if let ty::RawPtr(_, _) | ty::FnPtr(..) = lhs_ty.kind() {
                     // Raw and fn pointer operations are not allowed inside consts and thus not promotable.
-                    assert!(matches!(
+                    assert_matches!(
                         op,
                         BinOp::Eq
                             | BinOp::Ne
@@ -477,7 +477,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                             | BinOp::Ge
                             | BinOp::Gt
                             | BinOp::Offset
-                    ));
+                    );
                     return Err(Unpromotable);
                 }
 

compiler/rustc_mir_transform/src/shim.rs

@@ -996,7 +996,7 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
 /// }
 /// ```
 fn build_fn_ptr_addr_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> {
-    assert!(matches!(self_ty.kind(), ty::FnPtr(..)), "expected fn ptr, found {self_ty}");
+    assert_matches!(self_ty.kind(), ty::FnPtr(..), "expected fn ptr, found {self_ty}");
     let span = tcx.def_span(def_id);
     let Some(sig) = tcx.fn_sig(def_id).instantiate(tcx, &[self_ty.into()]).no_bound_vars() else {
         span_bug!(span, "FnPtr::addr with bound vars for `{self_ty}`");

compiler/rustc_parse/src/lib.rs

@@ -5,6 +5,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(if_let_guard)]

compiler/rustc_parse/src/parser/mod.rs

@@ -10,6 +10,7 @@ mod path;
 mod stmt;
 mod ty;
 
+use std::assert_matches::debug_assert_matches;
 use std::ops::Range;
 use std::{fmt, mem, slice};
 
@@ -1385,7 +1386,7 @@ impl<'a> Parser<'a> {
                     // can capture these tokens if necessary.
                     self.bump();
                     if self.token_cursor.stack.len() == target_depth {
-                        debug_assert!(matches!(self.token.kind, token::CloseDelim(_)));
+                        debug_assert_matches!(self.token.kind, token::CloseDelim(_));
                         break;
                     }
                 }

compiler/rustc_parse/src/parser/tests.rs

@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::io::prelude::*;
 use std::iter::Peekable;
 use std::path::{Path, PathBuf};
@@ -1747,7 +1748,7 @@ fn out_of_line_mod() {
         .unwrap();
 
         let ast::ItemKind::Mod(_, mod_kind) = &item.kind else { panic!() };
-        assert!(matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2));
+        assert_matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2);
     });
 }
 

compiler/rustc_target/src/spec/abi/tests.rs

@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use super::*;
 
 #[allow(non_snake_case)]
@@ -16,7 +18,7 @@ fn lookup_cdecl() {
 #[test]
 fn lookup_baz() {
     let abi = lookup("baz");
-    assert!(matches!(abi, Err(AbiUnsupported::Unrecognized)))
+    assert_matches!(abi, Err(AbiUnsupported::Unrecognized));
 }
 
 #[test]

compiler/rustc_trait_selection/src/solve/inspect/analyse.rs

@@ -9,6 +9,8 @@
 //! coherence right now and was annoying to implement, so I am leaving it
 //! as is until we start using it for something else.
 
+use std::assert_matches::assert_matches;
+
 use rustc_ast_ir::try_visit;
 use rustc_ast_ir::visit::VisitorResult;
 use rustc_infer::infer::{DefineOpaqueTypes, InferCtxt, InferOk};
@@ -273,10 +275,10 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
                     steps.push(step)
                 }
                 inspect::ProbeStep::MakeCanonicalResponse { shallow_certainty: c } => {
-                    assert!(matches!(
+                    assert_matches!(
                         shallow_certainty.replace(c),
                         None | Some(Certainty::Maybe(MaybeCause::Ambiguity))
-                    ));
+                    );
                 }
                 inspect::ProbeStep::NestedProbe(ref probe) => {
                     match probe.kind {

compiler/rustc_trait_selection/src/solve/normalize.rs

@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
@@ -63,7 +64,7 @@ where
     E: FromSolverError<'tcx, NextSolverError<'tcx>>,
 {
     fn normalize_alias_ty(&mut self, alias_ty: Ty<'tcx>) -> Result<Ty<'tcx>, Vec<E>> {
-        assert!(matches!(alias_ty.kind(), ty::Alias(..)));
+        assert_matches!(alias_ty.kind(), ty::Alias(..));
 
         let infcx = self.at.infcx;
         let tcx = infcx.tcx;

compiler/rustc_trait_selection/src/traits/misc.rs

@@ -1,5 +1,7 @@
 //! Miscellaneous type-system utilities that are too small to deserve their own modules.
 
+use std::assert_matches::assert_matches;
+
 use hir::LangItem;
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::FxIndexSet;
@@ -92,7 +94,7 @@ pub fn type_allowed_to_implement_const_param_ty<'tcx>(
     lang_item: LangItem,
     parent_cause: ObligationCause<'tcx>,
 ) -> Result<(), ConstParamTyImplementationError<'tcx>> {
-    assert!(matches!(lang_item, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy));
+    assert_matches!(lang_item, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy);
 
     let inner_tys: Vec<_> = match *self_type.kind() {
         // Trivially okay as these types are all:

compiler/rustc_ty_utils/src/layout_sanity_check.rs

@@ -249,7 +249,7 @@ pub(super) fn sanity_check_layout<'tcx>(
     if let Variants::Multiple { variants, .. } = &layout.variants {
         for variant in variants.iter() {
             // No nested "multiple".
-            assert!(matches!(variant.variants, Variants::Single { .. }));
+            assert_matches!(variant.variants, Variants::Single { .. });
             // Variants should have the same or a smaller size as the full thing,
             // and same for alignment.
             if variant.size > layout.size {