Merge json-2.2.0 from flori/json.

  https://github.com/flori/json/releases/tag/v2.2.0

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67127 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 29 insertions, 0 deletions

diff --git a/ext/json/lib/json/add/set.rb b/ext/json/lib/json/add/set.rb
new file mode 100644
index 0000000000..71e2a0ac8b
--- /dev/null
+++ b/ext/json/lib/json/add/set.rb
@@ -0,0 +1,29 @@
+unless defined?(::JSON::JSON_LOADED) and ::JSON::JSON_LOADED
+  require 'json'
+end
+defined?(::Set) or require 'set'
+
+class Set
+  # Import a JSON Marshalled object.
+  #
+  # method used for JSON marshalling support.
+  def self.json_create(object)
+    new object['a']
+  end
+
+  # Marshal the object to JSON.
+  #
+  # method used for JSON marshalling support.
+  def as_json(*)
+    {
+      JSON.create_id => self.class.name,
+      'a'            => to_a,
+    }
+  end
+
+  # return the JSON value
+  def to_json(*args)
+    as_json.to_json(*args)
+  end
+end
+