1 files changed, 20 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/inclusion.rb b/activesupport/lib/active_support/core_ext/object/inclusion.rb
new file mode 100644
index 0000000000..79e9fd6c88
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/inclusion.rb
@@ -0,0 +1,20 @@
+class Object
+  # Returns true if this object is included in the argument. Argument must be
+  # any object which respond to +#include?+. Usage:
+  #
+  #   characters = ["Konata", "Kagami", "Tsukasa"]
+  #   "Konata".in?(characters) # => true
+  #
+  def in?(another_object)
+    another_object.include?(self)
+  end
+
+  # Returns true if this object is included in the argument list. Usage:
+  #
+  #   username = "sikachu"
+  #   username.either?("josevalim", "dhh", "wycats") # => false
+  #
+  def either?(*objects)
+    objects.include?(self)
+  end
+end