merge revision(s) 57255,57256,57257: [Backport #13111]

	forwardable.rb: use defined?

	* lib/forwardable.rb (_delegator_method): use defined? operator
	  instead of binding and calling unbound Kernel#respond_to?.  a
	  remedy for an performance bottleneck.
	forwardable.rb: use defined?

	* lib/forwardable.rb (_delegator_method): use defined? operator
	  instead of binding and calling unbound Kernel#respond_to?.  a
	  remedy for an performance bottleneck.
	forwardable.rb: fix branches

	* lib/forwardable.rb (instance_delegate, single_delegate): fix
	  inverted branches.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57913 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 15 insertions, 13 deletions

diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index 0c04fb3a27..3662f56011 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -130,12 +130,13 @@ module Forwardable
   #    delegate [method, method, ...] => accessor
   #
   def instance_delegate(hash)
-    hash.each{ |methods, accessor|
-      methods = [methods] unless methods.respond_to?(:each)
-      methods.each{ |method|
-        def_instance_delegator(accessor, method)
-      }
-    }
+    hash.each do |methods, accessor|
+      unless defined?(methods.each)
+        def_instance_delegator(accessor, methods)
+      else
+        methods.each {|method| def_instance_delegator(accessor, method)}
+      end
+    end
   end
 
   #
@@ -204,7 +205,7 @@ module Forwardable
       mesg = "#{Module === obj ? obj : obj.class}\##{ali} at #{loc.path}:#{loc.lineno} forwarding to private method "
       method_call = "#{<<-"begin;"}\n#{<<-"end;".chomp}"
         begin;
-          unless ::Kernel.instance_method(:respond_to?).bind(_).call(:"#{method}")
+          unless defined? _.#{method}
             ::Kernel.warn "\#{caller_locations(1)[0]}: "#{mesg.dump}"\#{_.class}"'##{method}'
             _#{method_call}
           else
@@ -261,12 +262,13 @@ module SingleForwardable
   #    delegate [method, method, ...] => accessor
   #
   def single_delegate(hash)
-    hash.each{ |methods, accessor|
-      methods = [methods] unless methods.respond_to?(:each)
-      methods.each{ |method|
-        def_single_delegator(accessor, method)
-      }
-    }
+    hash.each do |methods, accessor|
+      unless defined?(methods.each)
+        def_single_delegator(accessor, methods)
+      else
+        methods.each {|method| def_single_delegator(accessor, method)}
+      end
+    end
   end
 
   #