From 4459989b0fe012a32faa073d8526b818f4063a85 Mon Sep 17 00:00:00 2001
From: Hans Fugal <fugalh@fb.com>
Date: Tue, 21 Oct 2014 10:24:14 -0700
Subject: [PATCH] (wangle) Fix a couple compilation issues

Summary: If you try to include files in a weird (but not incorrect) order you get compilation errors. No longer!

Test Plan: new dummy `cpp_binary` target

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, folly-diffs@, net-systems@, fugalh, exa, njormrod

FB internal diff: D1621083
---
 folly/wangle/Future.h               |  6 ++++++
 folly/wangle/Promise.h              |  2 +-
 folly/wangle/Try.h                  |  4 ++++
 folly/wangle/test/ClientCompile.cpp | 22 ++++++++++++++++++++++
 4 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 folly/wangle/test/ClientCompile.cpp

diff --git a/folly/wangle/Future.h b/folly/wangle/Future.h
index 4f0348ce..f3d50ce0 100644
--- a/folly/wangle/Future.h
+++ b/folly/wangle/Future.h
@@ -29,6 +29,12 @@
 
 namespace folly { namespace wangle {
 
+namespace detail {
+  template <class> struct Core;
+  template <class...> struct VariadicContext;
+}
+template <class> struct Promise;
+
 template <typename T> struct isFuture;
 
 template <class T>
diff --git a/folly/wangle/Promise.h b/folly/wangle/Promise.h
index 61bc0699..7442e451 100644
--- a/folly/wangle/Promise.h
+++ b/folly/wangle/Promise.h
@@ -17,7 +17,6 @@
 #pragma once
 
 #include <folly/wangle/Try.h>
-#include <folly/wangle/Future.h>
 
 namespace folly { namespace wangle {
 
@@ -98,4 +97,5 @@ private:
 
 }}
 
+#include <folly/wangle/Future.h>
 #include <folly/wangle/Promise-inl.h>
diff --git a/folly/wangle/Try.h b/folly/wangle/Try.h
index d13fffb5..68d3ef92 100644
--- a/folly/wangle/Try.h
+++ b/folly/wangle/Try.h
@@ -16,6 +16,10 @@
 
 #pragma once
 
+#include <type_traits>
+#include <exception>
+#include <algorithm>
+
 namespace folly { namespace wangle {
 
 template <class T>
diff --git a/folly/wangle/test/ClientCompile.cpp b/folly/wangle/test/ClientCompile.cpp
new file mode 100644
index 00000000..45ad8cd4
--- /dev/null
+++ b/folly/wangle/test/ClientCompile.cpp
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2014 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// amazing what things can go wrong if you include things in an unexpected
+// order.
+#include <folly/wangle/Try.h>
+#include <folly/wangle/Promise.h>
+#include <folly/wangle/Future.h>
+int main() { return 0; }
-- 
2.34.1