Rollup merge of #116358 - compiler-errors:match, r=lcnr

Rename both of the `Match` relations

Both of these names kinda were ambiguous.

r? lcnr

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

@@ -44,7 +44,7 @@ pub fn extract_verify_if_eq<'tcx>(
     test_ty: Ty<'tcx>,
 ) -> Option<ty::Region<'tcx>> {
     assert!(!verify_if_eq_b.has_escaping_bound_vars());
-    let mut m = Match::new(tcx, param_env);
+    let mut m = MatchAgainstHigherRankedOutlives::new(tcx, param_env);
     let verify_if_eq = verify_if_eq_b.skip_binder();
     m.relate(verify_if_eq.ty, test_ty).ok()?;
 
@@ -87,24 +87,32 @@ pub(super) fn can_match_erased_ty<'tcx>(
         // pointless micro-optimization
         true
     } else {
-        Match::new(tcx, param_env).relate(outlives_ty, erased_ty).is_ok()
+        MatchAgainstHigherRankedOutlives::new(tcx, param_env).relate(outlives_ty, erased_ty).is_ok()
     }
 }
 
-struct Match<'tcx> {
+struct MatchAgainstHigherRankedOutlives<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     pattern_depth: ty::DebruijnIndex,
     map: FxHashMap<ty::BoundRegion, ty::Region<'tcx>>,
 }
 
-impl<'tcx> Match<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Match<'tcx> {
-        Match { tcx, param_env, pattern_depth: ty::INNERMOST, map: FxHashMap::default() }
+impl<'tcx> MatchAgainstHigherRankedOutlives<'tcx> {
+    fn new(
+        tcx: TyCtxt<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+    ) -> MatchAgainstHigherRankedOutlives<'tcx> {
+        MatchAgainstHigherRankedOutlives {
+            tcx,
+            param_env,
+            pattern_depth: ty::INNERMOST,
+            map: FxHashMap::default(),
+        }
     }
 }
 
-impl<'tcx> Match<'tcx> {
+impl<'tcx> MatchAgainstHigherRankedOutlives<'tcx> {
     /// Creates the "Error" variant that signals "no match".
     fn no_match<T>(&self) -> RelateResult<'tcx, T> {
         Err(TypeError::Mismatch)
@@ -134,7 +142,7 @@ impl<'tcx> Match<'tcx> {
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for Match<'tcx> {
+impl<'tcx> TypeRelation<'tcx> for MatchAgainstHigherRankedOutlives<'tcx> {
     fn tag(&self) -> &'static str {
         "Match"
     }

compiler/rustc_middle/src/ty/_match.rs

@@ -18,20 +18,20 @@ use crate::ty::{self, InferConst, Ty, TyCtxt};
 /// Like subtyping, matching is really a binary relation, so the only
 /// important thing about the result is Ok/Err. Also, matching never
 /// affects any type variables or unification state.
-pub struct Match<'tcx> {
+pub struct MatchAgainstFreshVars<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
 }
 
-impl<'tcx> Match<'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Match<'tcx> {
-        Match { tcx, param_env }
+impl<'tcx> MatchAgainstFreshVars<'tcx> {
+    pub fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> MatchAgainstFreshVars<'tcx> {
+        MatchAgainstFreshVars { tcx, param_env }
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for Match<'tcx> {
+impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
     fn tag(&self) -> &'static str {
-        "Match"
+        "MatchAgainstFreshVars"
     }
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -39,6 +39,7 @@ use rustc_middle::dep_graph::dep_kinds;
 use rustc_middle::dep_graph::DepNodeIndex;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::traits::DefiningAnchor;
+use rustc_middle::ty::_match::MatchAgainstFreshVars;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::relate::TypeRelation;
@@ -2642,7 +2643,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
         current: ty::PolyTraitPredicate<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> bool {
-        let mut matcher = ty::_match::Match::new(self.tcx(), param_env);
+        let mut matcher = MatchAgainstFreshVars::new(self.tcx(), param_env);
         matcher.relate(previous, current).is_ok()
     }