[ruby/set] Resurrect support for Ruby 2.x

In Ruby 2.x, initialize_copy does not take a freeze option.

https://github.com/ruby/set/commit/3da6c309df

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/set.rb b/lib/set.rb
index d405d81178..844d52ed54 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -136,10 +136,18 @@ class Set
     @hash = orig.instance_variable_get(:@hash).dup
   end
 
-  # Clone internal hash.
-  def initialize_clone(orig, freeze: nil)
-    super
-    @hash = orig.instance_variable_get(:@hash).clone(freeze: freeze)
+  if Kernel.instance_method(:initialize_clone).arity != 1
+    # Clone internal hash.
+    def initialize_clone(orig, **options)
+      super
+      @hash = orig.instance_variable_get(:@hash).clone(**options)
+    end
+  else
+    # Clone internal hash.
+    def initialize_clone(orig)
+      super
+      @hash = orig.instance_variable_get(:@hash).clone
+    end
   end
 
   def freeze    # :nodoc: