1 files changed, 23 insertions, 4 deletions
diff --git a/prelude.rb b/prelude.rb
index b1e477a3ea..b6c610dd58 100644
--- a/prelude.rb
+++ b/prelude.rb
@@ -1,8 +1,18 @@
 class Binding
   # :nodoc:
-  def irb
-    require 'irb'
-    irb
+  def irb(...)
+    suppress = Thread.current[:__bundled_gems_warning_suppression]
+    Thread.current[:__bundled_gems_warning_suppression] = ['reline', 'rdoc']
+
+    begin
+      require 'irb'
+    rescue LoadError, Gem::LoadError
+      Gem::BUNDLED_GEMS.force_activate 'irb'
+      require 'irb'
+    end
+    irb(...)
+  ensure
+    Thread.current[:__bundled_gems_warning_suppression] = suppress
   end
 
   # suppress redefinition warning
@@ -10,13 +20,22 @@ class Binding
 end
 
 module Kernel
+  # :stopdoc:
   def pp(*objs)
     require 'pp'
     pp(*objs)
   end
 
   # suppress redefinition warning
-  alias pp pp # :nodoc:
+  alias pp pp
 
   private :pp
+  # :startdoc:
+end
+
+module Enumerable
+  # Makes a set from the enumerable object with given arguments.
+  def to_set(&block)
+    Set.new(self, &block)
+  end
 end