Atos C++ Developer interview questions

2nd technical round advanced C++ concepts. Difference in unique _lock and lock_guard, What is function object, What is core dump, Find greatest of 3 numbers (using max function expected), Singeltone and Strategy design pattern, Static method and Static object, Friend fun vs Friend class, Difference in error and exception, Function object, Lambda expression, How to stop making class object(Expected answer is to make constructor as delete). Basic STL Algorithm Library functions like max, sort, find, etc.