Outline throw statements in folly/futures/

[folly.git] / folly / futures / Promise-inl.h

diff --git a/folly/futures/Promise-inl.h b/folly/futures/Promise-inl.h
index 1f4b7aa39f0137bda8911b0135f4ae96bbb75176..3c6ff17345965552b303bb943638fe0c046e0f4e 100644 (file)
--- a/folly/futures/Promise-inl.h
+++ b/folly/futures/Promise-inl.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 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.
@@ -25,37 +25,49 @@
 namespace folly {
 
 template <class T>
-Promise<T>::Promise() : retrieved_(false), core_(new detail::Core<T>())
-{}
+Promise<T> Promise<T>::makeEmpty() noexcept {
+  return Promise<T>(futures::detail::EmptyConstruct{});
+}
+
+template <class T>
+Promise<T>::Promise()
+    : retrieved_(false), core_(new futures::detail::Core<T>()) {}
 
 template <class T>
 Promise<T>::Promise(Promise<T>&& other) noexcept
     : retrieved_(other.retrieved_), core_(other.core_) {
   other.core_ = nullptr;
+  other.retrieved_ = false;
 }
 
 template <class T>
 Promise<T>& Promise<T>::operator=(Promise<T>&& other) noexcept {
-  retrieved_ = other.retrieved_;
-  core_ = other.core_;
-  other.core_ = nullptr;
+  std::swap(core_, other.core_);
+  std::swap(retrieved_, other.retrieved_);
   return *this;
 }
 
 template <class T>
 void Promise<T>::throwIfFulfilled() {
-  if (!core_)
-    throw NoState();
-  if (core_->ready())
-    throw PromiseAlreadySatisfied();
+  if (!core_) {
+    throwNoState();
+  }
+  if (core_->ready()) {
+    throwPromiseAlreadySatisfied();
+  }
 }
 
 template <class T>
 void Promise<T>::throwIfRetrieved() {
-  if (retrieved_)
-    throw FutureAlreadyRetrieved();
+  if (retrieved_) {
+    throwFutureAlreadyRetrieved();
+  }
 }
 
+template <class T>
+Promise<T>::Promise(futures::detail::EmptyConstruct) noexcept
+    : retrieved_(false), core_(nullptr) {}
+
 template <class T>
 Promise<T>::~Promise() {
   detach();
@@ -109,7 +121,7 @@ void Promise<T>::setInterruptHandler(
 }
 
 template <class T>
-void Promise<T>::fulfilTry(Try<T> t) {
+void Promise<T>::setTry(Try<T>&& t) {
   throwIfFulfilled();
   core_->setResult(std::move(t));
 }
@@ -120,22 +132,22 @@ void Promise<T>::setValue(M&& v) {
   static_assert(!std::is_same<T, void>::value,
                 "Use setValue() instead");
 
-  fulfilTry(Try<T>(std::forward<M>(v)));
+  setTry(Try<T>(std::forward<M>(v)));
 }
 
 template <class T>
-void Promise<T>::setValue() {
-  static_assert(std::is_same<T, void>::value,
-                "Use setValue(value) instead");
-
-  fulfilTry(Try<void>());
+template <class F>
+void Promise<T>::setWith(F&& func) {
+  throwIfFulfilled();
+  setTry(makeTryWith(std::forward<F>(func)));
 }
 
 template <class T>
-template <class F>
-void Promise<T>::fulfil(F&& func) {
-  throwIfFulfilled();
-  fulfilTry(makeTryFunction(std::forward<F>(func)));
+bool Promise<T>::isFulfilled() const noexcept {
+  if (core_) {
+    return core_->hasResult();
+  }
+  return true;
 }
 
 }