Type generalization should not look at opaque type in coherence

oli-obk · oli-obk · commit 7301cd784437 · 2022-11-21T16:38:23.000Z
diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
@@ -548,8 +548,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
     }
 
     fn mark_ambiguous(&mut self) {
-        // The generalizer always compares types against themselves,
-        // and thus doesn't really take part in coherence.
+        self.infcx.tcx.sess.delay_span_bug(self.cause.span, "opaque types are handled in `tys`");
     }
 
     fn binders<T>(

Original file line number	Diff line number	Diff line change
`@@ -548,8 +548,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {`
`548`	`548`	`}`
`549`	`549`
`550`	`550`	`fn mark_ambiguous(&mut self) {`
`551`		`- // The generalizer always compares types against themselves,`
`552`		`- // and thus doesn't really take part in coherence.`
	`551`	+ self.infcx.tcx.sess.delay_span_bug(self.cause.span, "opaque types are handled in `tys`");
`553`	`552`	`}`
`554`	`553`
`555`	`554`	`fn binders<T>(`