1 files changed, 21 insertions, 0 deletions
diff --git a/src/mongo/db/matcher/expression_array.cpp b/src/mongo/db/matcher/expression_array.cpp
index b80e321b976..84c544df2bf 100644
--- a/src/mongo/db/matcher/expression_array.cpp
+++ b/src/mongo/db/matcher/expression_array.cpp
@@ -108,6 +108,14 @@ void ElemMatchObjectMatchExpression::serialize(BSONObjBuilder* out) const {
     out->append(path(), BSON("$elemMatch" << subBob.obj()));
 }
 
+MatchExpression::ExpressionOptimizerFunc ElemMatchObjectMatchExpression::getOptimizer() const {
+    return [](std::unique_ptr<MatchExpression> expression) {
+        auto& elemExpression = static_cast<ElemMatchObjectMatchExpression&>(*expression);
+        elemExpression._sub = MatchExpression::optimize(std::move(elemExpression._sub));
+
+        return expression;
+    };
+}
 
 // -------
 
@@ -184,6 +192,19 @@ void ElemMatchValueMatchExpression::serialize(BSONObjBuilder* out) const {
     out->append(path(), BSON("$elemMatch" << emBob.obj()));
 }
 
+MatchExpression::ExpressionOptimizerFunc ElemMatchValueMatchExpression::getOptimizer() const {
+    return [](std::unique_ptr<MatchExpression> expression) {
+        auto& subs = static_cast<ElemMatchValueMatchExpression&>(*expression)._subs;
+
+        for (MatchExpression*& subExpression : subs) {
+            auto optimizedSubExpression =
+                MatchExpression::optimize(std::unique_ptr<MatchExpression>(subExpression));
+            subExpression = optimizedSubExpression.release();
+        }
+
+        return expression;
+    };
+}
 
 // ---------