New cpp folder structure

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

libs/platform/safe_callback.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "platform/platform.hpp"
+
+#include <future>
+#include <functional>
+#include <utility>
+
+namespace platform
+{
+template <typename T>
+class SafeCallback;
+
+// Calls callback on main thread, all params are copied.
+// If not initialized nothing will be done.
+// *NOTE* The class is not thread-safe.
+template <typename R, typename ...Args>
+class SafeCallback<R(Args...)>
+{
+public:
+  SafeCallback() = default;
+
+  template <typename Fn>
+  SafeCallback(Fn const & fn)
+    : m_fn(fn)
+  {
+  }
+
+  operator bool() const noexcept
+  {
+    return static_cast<bool>(m_fn);
+  }
+
+  void operator()(Args... args) const
+  {
+    if (m_fn)
+      GetPlatform().RunTask(Platform::Thread::Gui, std::bind(m_fn, std::move(args)...));
+  }
+
+private:
+  std::function<R(Args...)> m_fn;
+};
+}  // namespace platform