message: i think old gcc needs a move here
diff: @@ -48,7 +48,7 @@ unique_ptr<Expression> RegexOptimizationRule::Apply(LogicalOperator &op, vector<
  move(root->children), nullptr);
  contains->children[1] = make_unique<BoundConstantExpression>(Value(patt_str));
  - return contains;
  + return move(contains);
  }
  return nullptr;
  }
  