Re-use the fresh InferCtxt

Author: Aaron1011

compiler/rustc_trait_selection/src/traits/project.rs

@@ -947,32 +947,32 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
 
             let tcx = selcx.infcx().tcx;
 
-            result.obligations.drain_filter(|projected_obligation| {
-                // If any global obligations always apply, considering regions, then we don't
-                // need to include them. The `is_global` check rules out inference variables,
-                // so there's no need for the caller of `opt_normalize_projection_type`
-                // to evaluate them.
-                // Note that we do *not* discard obligations that evaluate to
-                // `EvaluatedtoOkModuloRegions`. Evaluating these obligations
-                // inside of a query (e.g. `evaluate_obligation`) can change
-                // the result to `EvaluatedToOkModuloRegions`, while an
-                // `EvaluatedToOk` obligation will never change the result.
-                // See #85360 for more details
-                if !projected_obligation.is_global(tcx) {
-                    return false;
-                }
-
-                // We create a fresh `InferCtxt` for each predicate we speculatively evaluate,
-                // so that we won't create (and cache) any spurious projection cycles in the main
-                // `InferCtxt`
-                tcx.infer_ctxt().enter(|infcx| {
-                    let mut canonical =
-                        SelectionContext::with_query_mode(&infcx, TraitQueryMode::Canonical);
+            // We create a fresh `InferCtxt` for speculative evaluation
+            // so that we won't create (and cache) any spurious projection cycles in the main
+            // `InferCtxt`
+            tcx.infer_ctxt().enter(|infcx| {
+                let mut canonical =
+                    SelectionContext::with_query_mode(&infcx, TraitQueryMode::Canonical);
+
+                result.obligations.drain_filter(|projected_obligation| {
+                    // If any global obligations always apply, considering regions, then we don't
+                    // need to include them. The `is_global` check rules out inference variables,
+                    // so there's no need for the caller of `opt_normalize_projection_type`
+                    // to evaluate them.
+                    // Note that we do *not* discard obligations that evaluate to
+                    // `EvaluatedtoOkModuloRegions`. Evaluating these obligations
+                    // inside of a query (e.g. `evaluate_obligation`) can change
+                    // the result to `EvaluatedToOkModuloRegions`, while an
+                    // `EvaluatedToOk` obligation will never change the result.
+                    // See #85360 for more details
+                    if !projected_obligation.is_global(tcx) {
+                        return false;
+                    }
 
                     canonical
                         .evaluate_root_obligation(projected_obligation)
                         .map_or(false, |res| res.must_apply_considering_regions())
-                })
+                });
             });
 
             if use_cache {