Object#returning has gone, it's already deprecated on 3-0-stable

activesupport/lib/active_support/core_ext/object.rb

@@ -2,7 +2,6 @@
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/object/duplicable'
 require 'active_support/core_ext/object/try'
-require 'active_support/core_ext/object/returning'
 
 require 'active_support/core_ext/object/conversions'
 require 'active_support/core_ext/object/instance_variables'

activesupport/lib/active_support/core_ext/object/returning.rb

-class Object
-  # Returns +value+ after yielding +value+ to the block. This simplifies the
-  # process of constructing an object, performing work on the object, and then
-  # returning the object from a method. It is a Ruby-ized realization of the K
-  # combinator, courtesy of Mikael Brockman.
-  #
-  # ==== Examples
-  #
-  #  # Without returning
-  #  def foo
-  #    values = []
-  #    values << "bar"
-  #    values << "baz"
-  #    return values
-  #  end
-  #
-  #  foo # => ['bar', 'baz']
-  #
-  #  # returning with a local variable
-  #  def foo
-  #    returning values = [] do
-  #      values << 'bar'
-  #      values << 'baz'
-  #    end
-  #  end
-  #
-  #  foo # => ['bar', 'baz']
-  #
-  #  # returning with a block argument
-  #  def foo
-  #    returning [] do |values|
-  #      values << 'bar'
-  #      values << 'baz'
-  #    end
-  #  end
-  #
-  #  foo # => ['bar', 'baz']
-  def returning(value)
-    ActiveSupport::Deprecation.warn('Object#returning has been deprecated in favor of Object#tap.', caller)
-    yield(value)
-    value
-  end
-end
\ No newline at end of file