New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/base/thread_checker.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "base/assert.hpp"
+#include "base/macros.hpp"
+
+#include <thread>
+
+/// This class remembers id of a thread on which it was created, and
+/// then can be used to verify that CalledOnOriginalThread() is called
+/// from a thread on which it was created.
+class ThreadChecker
+{
+public:
+  ThreadChecker();
+
+  /// \return True if this method is called from a thread on which
+  ///         current ThreadChecker's instance was created, false otherwise.
+  bool CalledOnOriginalThread() const;
+
+private:
+  std::thread::id const m_id;
+
+  DISALLOW_COPY_AND_MOVE(ThreadChecker);
+};
+
+#define DECLARE_THREAD_CHECKER(threadCheckerName) ThreadChecker threadCheckerName
+#define CHECK_THREAD_CHECKER(threadCheckerName, msg) CHECK(threadCheckerName.CalledOnOriginalThread(), msg)
+#define DECLARE_AND_CHECK_THREAD_CHECKER(msg) \
+{ \
+  static const ThreadChecker threadChecker; \
+  CHECK(threadChecker.CalledOnOriginalThread(), (msg)); \
+}