From bb1ea5d1517935af9ddd5aa74ed12fffc373f0fb Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Sat, 5 Oct 2024 21:42:44 -0700
Subject: [PATCH] Reapply "Attempted fix"

This reverts commit 7999d7464e04d6ab9e6b67df204a7f0f3bbe1cf2.
---
 lib/or-tools.rb             | 2 +-
 lib/or_tools/constant.rb    | 4 +++-
 lib/or_tools/linear_expr.rb | 6 +++++-
 lib/or_tools/product_cst.rb | 4 +++-
 lib/or_tools/sum_array.rb   | 4 +++-
 5 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/lib/or-tools.rb b/lib/or-tools.rb
index 884d571..3ca94af 100644
--- a/lib/or-tools.rb
+++ b/lib/or-tools.rb
@@ -5,7 +5,6 @@
 require_relative "or_tools/comparison"
 require_relative "or_tools/comparison_operators"
 require_relative "or_tools/bool_var"
-require_relative "or_tools/constant"
 require_relative "or_tools/cp_model"
 require_relative "or_tools/cp_solver"
 require_relative "or_tools/cp_solver_solution_callback"
@@ -13,6 +12,7 @@
 require_relative "or_tools/knapsack_solver"
 require_relative "or_tools/linear_constraint"
 require_relative "or_tools/linear_expr"
+require_relative "or_tools/constant"
 require_relative "or_tools/mp_variable"
 require_relative "or_tools/product_cst"
 require_relative "or_tools/routing_index_manager"
diff --git a/lib/or_tools/constant.rb b/lib/or_tools/constant.rb
index fbeebe0..4a58cda 100644
--- a/lib/or_tools/constant.rb
+++ b/lib/or_tools/constant.rb
@@ -1,5 +1,7 @@
 module ORTools
-  class Constant < LinearExpr
+  class Constant
+    include LinearExprUtils
+
     def initialize(val)
       @val = val
     end
diff --git a/lib/or_tools/linear_expr.rb b/lib/or_tools/linear_expr.rb
index 3d05657..b910f10 100644
--- a/lib/or_tools/linear_expr.rb
+++ b/lib/or_tools/linear_expr.rb
@@ -1,5 +1,5 @@
 module ORTools
-  class LinearExpr
+  module LinearExprUtils
     def solution_value
       coeffs.sum { |var, coeff| var.solution_value * coeff }
     end
@@ -82,4 +82,8 @@ def coerce(other)
       end
     end
   end
+
+  class LinearExpr
+    include LinearExprUtils
+  end
 end
diff --git a/lib/or_tools/product_cst.rb b/lib/or_tools/product_cst.rb
index 48e1d94..704f55f 100644
--- a/lib/or_tools/product_cst.rb
+++ b/lib/or_tools/product_cst.rb
@@ -1,5 +1,7 @@
 module ORTools
-  class ProductCst < LinearExpr
+  class ProductCst
+    include LinearExprUtils
+
     attr_reader :expr, :coef
 
     def initialize(expr, coef)
diff --git a/lib/or_tools/sum_array.rb b/lib/or_tools/sum_array.rb
index dc6accc..7a2792f 100644
--- a/lib/or_tools/sum_array.rb
+++ b/lib/or_tools/sum_array.rb
@@ -1,5 +1,7 @@
 module ORTools
-  class SumArray < LinearExpr
+  class SumArray
+    include LinearExprUtils
+
     attr_reader :array
 
     def initialize(array)