Add way to get upper and lower bounds of SatIntVar (#45)

Author: johnnymo87

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.10.1 (2023-03-17)
+
+- Add way to get upper and lower bounds of `SatIntVar`
+
 ## 0.10.0 (2023-03-15)
 
 - Updated OR-Tools to 9.6

ext/or-tools/constraint.cpp

@@ -3,6 +3,7 @@
 
 #include "ext.h"
 
+using operations_research::Domain;
 using operations_research::sat::BoolVar;
 using operations_research::sat::Constraint;
 using operations_research::sat::CpModelBuilder;
@@ -98,8 +99,13 @@ namespace Rice::detail
 }
 
 void init_constraint(Rice::Module& m) {
+  Rice::define_class_under<Domain>(m, "Domain")
+    .define_method("min", &Domain::Min)
+    .define_method("max", &Domain::Max);
+
   rb_cSatIntVar = Rice::define_class_under<IntVar>(m, "SatIntVar")
-    .define_method("name", &IntVar::Name);
+    .define_method("name", &IntVar::Name)
+    .define_method("domain", &IntVar::Domain);
 
   Rice::define_class_under<IntervalVar>(m, "SatIntervalVar")
     .define_method("name", &IntervalVar::Name);

test/constraint_test.rb

@@ -234,6 +234,17 @@ def test_add_hint
     end
   end
 
+  def test_int_var_domain
+    model = ORTools::CpModel.new
+
+    lower_bound = (0..9).to_a.sample
+    upper_bound = (10..19).to_a.sample
+    x = model.new_int_var(lower_bound, upper_bound, "x")
+
+    assert_equal lower_bound, x.domain.min
+    assert_equal upper_bound, x.domain.max
+  end
+
   def test_sum_empty_true
     model = ORTools::CpModel.new
     model.add([].sum < 2)