object.c: Module#singleton_class?

* object.c (rb_mod_singleton_p): new method Module#singleton_class? to
  return whether the receiver is a singleton class or not.
  [ruby-core:51087] [Feature #7609]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42449 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 6 insertions, 0 deletions

diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 7aed078654..47848f3184 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -346,4 +346,10 @@ class TestClass < Test::Unit::TestCase
     assert_empty(added.grep(->(k) {c == k[0]}), bug5283)
     assert_equal(:foo, d.foo)
   end
+
+  def test_singleton_class_p
+    feature7609 = '[ruby-core:51087] [Feature #7609]'
+    assert_predicate(self.singleton_class, :singleton_class?, feature7609)
+    assert_not_predicate(self.class, :singleton_class?, feature7609)
+  end
 end