1 files changed, 31 insertions, 0 deletions
diff --git a/activerecord/lib/arel/collectors/composite.rb b/activerecord/lib/arel/collectors/composite.rb
new file mode 100644
index 0000000000..0533544993
--- /dev/null
+++ b/activerecord/lib/arel/collectors/composite.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Collectors
+    class Composite
+      def initialize(left, right)
+        @left = left
+        @right = right
+      end
+
+      def <<(str)
+        left << str
+        right << str
+        self
+      end
+
+      def add_bind(bind, &block)
+        left.add_bind bind, &block
+        right.add_bind bind, &block
+        self
+      end
+
+      def value
+        [left.value, right.value]
+      end
+
+      private
+        attr_reader :left, :right
+    end
+  end
+end