text: import unittest
  
  from Cython.Compiler import PyrexTypes as pt
  from Cython.Compiler.ExprNodes import NameNode
  from Cython.Compiler.PyrexTypes import CFuncTypeArg
  
  def cfunctype(*arg_types):
      return pt.CFuncType(pt.c_int_type,
          [ CFuncTypeArg("name", arg_type, None) for arg_type in arg_types ])
  
  def cppclasstype(name, base_classes):
      return pt.CppClassType(name, None, 'CPP_'+name, base_classes)
  
  class SignatureMatcherTest(unittest.TestCase):
      """
      Test the signature matching algorithm for overloaded signatures.
      """
      def assertMatches(self, expected_type, arg_types, functions):
          match = pt.best_match(arg_types, functions)
          if expected_type is not None:
              self.assertNotEqual(None, match)
          self.assertEqual(expected_type, match.type)
  
      def test_cpp_reference_single_arg(self):
          function_types = [
              cfunctype(pt.CReferenceType(pt.c_int_type)),
              cfunctype(pt.CReferenceType(pt.c_long_type)),
              cfunctype(pt.CReferenceType(pt.c_double_type)),
              ]
  
          functions = [ NameNode(None, type=t) for t in function_types ]
          self.assertMatches(function_types[0], [pt.c_int_type], functions)
          self.assertMatches(function_types[1], [pt.c_long_type], functions)
          self.assertMatches(function_types[2], [pt.c_double_type], functions)
  
      def test_cpp_reference_two_args(self):
          function_types = [
              cfunctype(
                  pt.CReferenceType(pt.c_int_type), pt.CReferenceType(pt.c_long_type)),
              cfunctype(
                  pt.CReferenceType(pt.c_long_type), pt.CReferenceType(pt.c_long_type)),
              ]
  
          functions = [ NameNode(None, type=t) for t in function_types ]
          self.assertMatches(function_types[0], [pt.c_int_type, pt.c_long_type], functions)
          self.assertMatches(function_types[1], [pt.c_long_type, pt.c_long_type], functions)
          self.assertMatches(function_types[1], [pt.c_long_type, pt.c_int_type], functions)
  
      def test_cpp_reference_cpp_class(self):
          classes = [ cppclasstype("Test%d" % i, []) for i in range(2) ]
          function_types = [
              cfunctype(pt.CReferenceType(classes[0])),
              cfunctype(pt.CReferenceType(classes[1])),
              ]
  
          functions = [ NameNode(None, type=t) for t in function_types ]
          self.assertMatches(function_types[0], [classes[0]], functions)
          self.assertMatches(function_types[1], [classes[1]], functions)
  
      def test_cpp_reference_cpp_class_and_int(self):
          classes = [ cppclasstype("Test%d" % i, []) for i in range(2) ]
          function_types = [
              cfunctype(pt.CReferenceType(classes[0]), pt.c_int_type),
              cfunctype(pt.CReferenceType(classes[0]), pt.c_long_type),
              cfunctype(pt.CReferenceType(classes[1]), pt.c_int_type),
              cfunctype(pt.CReferenceType(classes[1]), pt.c_long_type),
              ]
  
          functions = [ NameNode(None, type=t) for t in function_types ]
          self.assertMatches(function_types[0], [classes[0], pt.c_int_type], functions)
          self.assertMatches(function_types[1], [classes[0], pt.c_long_type], functions)
          self.assertMatches(function_types[2], [classes[1], pt.c_int_type], functions)
          self.assertMatches(function_types[3], [classes[1], pt.c_long_type], functions)
  