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.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57255 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index 0c04fb3a27..cc5ac15001 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -131,7 +131,7 @@ module Forwardable
   #
   def instance_delegate(hash)
     hash.each{ |methods, accessor|
-      methods = [methods] unless methods.respond_to?(:each)
+      methods = [methods] unless defined?(methods.each)
       methods.each{ |method|
         def_instance_delegator(accessor, method)
       }
@@ -204,7 +204,7 @@ 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
@@ -262,7 +262,7 @@ module SingleForwardable
   #
   def single_delegate(hash)
     hash.each{ |methods, accessor|
-      methods = [methods] unless methods.respond_to?(:each)
+      methods = [methods] unless defined?(methods.each)
       methods.each{ |method|
         def_single_delegator(accessor, method)
       }