SERVER-29564 BSONObjBuilder can now be seeded with a BSONObj prefix

This will avoid copying whenever it is safe.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/mongo/client/query.h b/src/mongo/client/query.h
index 4a4a97bd9b8..3ced9c591f4 100644
--- a/src/mongo/client/query.h
+++ b/src/mongo/client/query.h
@@ -164,8 +164,7 @@ private:
     template <class T>
     void appendComplex(const char* fieldName, const T& val) {
         makeComplex();
-        BSONObjBuilder b;
-        b.appendElements(obj);
+        BSONObjBuilder b(std::move(obj));
         b.append(fieldName, val);
         obj = b.obj();
     }