Cut some includes from Executor.h

Summary: [Folly] Cut some includes from `Executor.h`.

Reviewed By: mzlee

Differential Revision: D4256618

fbshipit-source-id: 1728f48b3c0ec4e0c4c84c44bd8afb583d438129

folly/Executor.cpp

+/*
+ * Copyright 2016 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.
+ */
+
+#include <folly/Executor.h>
+
+#include <stdexcept>
+
+namespace folly {
+
+void Executor::addWithPriority(Func, int8_t /* priority */) {
+  throw std::runtime_error(
+      "addWithPriority() is not implemented for this Executor");
+}
+}

folly/Executor.h

@@ -16,10 +16,7 @@
 
 #pragma once
 
-#include <atomic>
 #include <climits>
-#include <functional>
-#include <stdexcept>
 
 #include <folly/Function.h>
 
@@ -39,10 +36,7 @@ class Executor {
 
   /// Enqueue a function with a given priority, where 0 is the medium priority
   /// This is up to the implementation to enforce
-  virtual void addWithPriority(Func, int8_t /*priority*/) {
-    throw std::runtime_error(
-        "addWithPriority() is not implemented for this Executor");
-  }
+  virtual void addWithPriority(Func, int8_t priority);
 
   virtual uint8_t getNumPriorities() const {
     return 1;

folly/Makefile.am

@@ -413,6 +413,7 @@ libfolly_la_SOURCES = \
 	detail/IPAddress.cpp \
 	dynamic.cpp \
 	ExceptionWrapper.cpp \
+	Executor.cpp \
 	File.cpp \
 	FileUtil.cpp \
 	FingerprintTables.cpp \