1 files changed, 24 insertions, 2 deletions
diff --git a/msgpack/__init__.py b/msgpack/__init__.py
index a7b47b1..56a0b36 100644
--- a/msgpack/__init__.py
+++ b/msgpack/__init__.py
@@ -2,9 +2,31 @@
 from msgpack._version import version
 from msgpack.exceptions import *
 
-from collections import namedtuple
 
-ExtType = namedtuple('ExtType', 'code data')
+class ExtType(object):
+    __slots__ = ('code', 'data')
+
+    def __init__(self, code, data):
+        if not isinstance(code, int):
+            raise TypeError("code must be int")
+        if not isinstance(data, bytes):
+            raise TypeError("data must be bytes")
+        if not 0 <= code <= 127:
+            raise ValueError("code must be 0~127")
+        self.code = code
+        self.data = data
+
+    def __eq__(self, other):
+        if not isinstance(other, ExtType):
+            return NotImplemented
+        return self.code == other.code and self.data == other.data
+
+    def __hash__(self):
+        return self.code ^ hash(self.data)
+
+    def __repr__(self):
+        return "msgpack.ExtType(%r, %r)" % (self.code, self.data)
+
 
 import os
 if os.environ.get('MSGPACK_PUREPYTHON'):