X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2Ffutures%2FPromise.h;h=905ce5dd7eb9a4a1d23864aed407381920ad3728;hb=f2925b23df8d85ebca72d62a69f1282528c086de;hp=b18f59b2808d59f5b365c6f890c5f87e3489ee43;hpb=a56a988a8cd07c7e3250f27594b8f92c9274b30d;p=folly.git

diff --git a/folly/futures/Promise.h b/folly/futures/Promise.h
index b18f59b2..905ce5dd 100644
--- a/folly/futures/Promise.h
+++ b/folly/futures/Promise.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,11 +23,23 @@
 namespace folly {
 
 // forward declaration
+template <class T>
+class SemiFuture;
 template <class T> class Future;
 
+namespace futures {
+namespace detail {
+struct EmptyConstruct {};
+template <typename T, typename F>
+class CoreCallbackState;
+} // namespace detail
+} // namespace futures
+
 template <class T>
 class Promise {
-public:
+ public:
+  static Promise<T> makeEmpty() noexcept; // equivalent to moved-from
+
   Promise();
   ~Promise();
 
@@ -93,11 +105,15 @@ public:
   template <class F>
   void setWith(F&& func);
 
-  bool isFulfilled();
+  bool isFulfilled() const noexcept;
 
-private:
+ private:
   typedef typename Future<T>::corePtr corePtr;
+  template <class>
+  friend class SemiFuture;
   template <class> friend class Future;
+  template <class, class>
+  friend class futures::detail::CoreCallbackState;
 
   // Whether the Future has been retrieved (a one-time operation).
   bool retrieved_;
@@ -105,12 +121,14 @@ private:
   // shared core state object
   corePtr core_;
 
+  explicit Promise(futures::detail::EmptyConstruct) noexcept;
+
   void throwIfFulfilled();
   void throwIfRetrieved();
   void detach();
 };
 
-}
+} // namespace folly
 
 #include <folly/futures/Future.h>
 #include <folly/futures/Promise-inl.h>