Simplify RegionConstraintCollector::vars_since_snapshot

varkor · varkor · commit 2a08860ae6ec · 2019-03-27T09:44:55.000Z
diff --git a/src/librustc/infer/region_constraints/mod.rs b/src/librustc/infer/region_constraints/mod.rs
@@ -841,12 +841,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
     }
 
     pub fn vars_since_snapshot(&self, mark: &RegionSnapshot) -> Vec<RegionVid> {
-        self.undo_log[mark.length..]
-            .iter()
-            .filter_map(|&elt| match elt {
-                AddVar(vid) => Some(vid),
-                _ => None,
-            }).collect()
+        self.unification_table.vars_since_snapshot(&mark.region_snapshot).collect()
     }
 
     /// See [`RegionInference::region_constraints_added_in_snapshot`].

Original file line number	Diff line number	Diff line change
`@@ -841,12 +841,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {`
`841`	`841`	`}`
`842`	`842`
`843`	`843`	`pub fn vars_since_snapshot(&self, mark: &RegionSnapshot) -> Vec<RegionVid> {`
`844`		`- self.undo_log[mark.length..]`
`845`		`- .iter()`
`846`		`- .filter_map(\|&elt\| match elt {`
`847`		`- AddVar(vid) => Some(vid),`
`848`		`- _ => None,`
`849`		`- }).collect()`
	`844`	`+ self.unification_table.vars_since_snapshot(&mark.region_snapshot).collect()`
`850`	`845`	`}`
`851`	`846`
`852`	`847`	/// See [`RegionInference::region_constraints_added_in_snapshot`].