Allow DelegateClass() to module_eval given block

Methods that return classes often module_eval the given block
(e.g. Class.new and Struct.new).  This allows DelegateClass to
work similarly.  This makes it easier to use DelegateClass
directly without subclassing, so as not to create an unnecessary
subclass.

Implements [Feature #15842]

1 files changed, 7 insertions, 0 deletions

diff --git a/test/test_delegate.rb b/test/test_delegate.rb
index ffc4d9527e..8ed3342afa 100644
--- a/test/test_delegate.rb
+++ b/test/test_delegate.rb
@@ -22,6 +22,13 @@ class TestDelegateClass < Test::Unit::TestCase
     assert_equal(:m, obj.m, "[ruby-dev:33116]")
   end
 
+  def test_delegate_class_block
+    klass = DelegateClass(Array) do
+      alias foo first
+    end
+    assert_equal(1, klass.new([1]).foo)
+  end
+
   def test_systemcallerror_eq
     e = SystemCallError.new(0)
     assert((SimpleDelegator.new(e) == e) == (e == SimpleDelegator.new(e)), "[ruby-dev:34808]")