virtual inheritance,singleton ,mutithreaded singleton,seamphore,livelock,difference between TCP/UDP.Factory pattern ,prototype pattern . Virtual table ,why destructor should be virtual ,can constructor be virtual ? how can we achieve . Data structure . write operation for own hashtable . time complexity of Binary tree. What is red black tree . simple STL , current project , challenges in project which you have faced ? output of program ,RTTI . Dynamic cast and how it works . initializer list and why we need them. when initializer list is mandatory give the example . what are the problem we face in multithreading ? Auto pointer and shared pointer what is the difference . can container have pointer of objects and reason ? these are the questions have been asked . + few more which i can not recollect but all are fundamentals .