Core/Threading: Create ThreadPool class

(cherry picked from commit d82b2b1a67)

src/common/Threading/ThreadPool.h

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TRINITY_THREAD_POOL_H
+#define TRINITY_THREAD_POOL_H
+
+#include <boost/asio/post.hpp>
+#include <boost/asio/thread_pool.hpp>
+#include <thread>
+
+namespace Trinity
+{
+class ThreadPool
+{
+public:
+    explicit ThreadPool(std::size_t numThreads = std::thread::hardware_concurrency()) : _impl(numThreads) { }
+
+    template<typename T>
+    decltype(auto) PostWork(T&& work)
+    {
+        return boost::asio::post(_impl, std::forward<T>(work));
+    }
+
+    void Join()
+    {
+        _impl.join();
+    }
+
+private:
+    boost::asio::thread_pool _impl;
+};
+}
+
+#endif // TRINITY_THREAD_POOL_H