Update C++ references and add advanced reference link

Author: VR-Rathod

pages/C++.md

@@ -724,4 +724,5 @@
 	- [C++ Roadmap](https://github.com/salmer/CppDeveloperRoadmap)
 	- [Cheat Sheets for c++](https://hackingcpp.com/cpp/cheat_sheets.html)
 	- [Docs Book](https://cplusplus.com/doc/tutorial/)
-	- [C++ references](https://en.cppreference.com/w/)
+	- [C++ references](https://en.cppreference.com/w/)
+   	- [C++ Advance Ref.](https://en.cppreference.com/w/cpp/utility/functional/ref.html)