avoid executing the discriminator functions multiple times

1 files changed, 5 insertions, 1 deletions

diff --git a/pyramid/registry.py b/pyramid/registry.py
index 1073134ff..df9a10822 100644
--- a/pyramid/registry.py
+++ b/pyramid/registry.py
@@ -255,9 +255,13 @@ class Deferred(object):
     def __init__(self, func):
         self.func = func
 
-    def resolve(self):
+    @reify
+    def value(self):
         return self.func()
 
+    def resolve(self):
+        return self.value
+
 def undefer(v):
     """ Function which accepts an object and returns it unless it is a
     :class:`pyramid.registry.Deferred` instance.  If it is an instance of