IBM Applications Developer interview questions

How do you rate yourself on c++ ? (this they ll ask to see our confidence i think ) what are the 3 pillars of oops or c++ 1)what is virtual destructor, example code 2)Dynamic cast 3)Smart pointers, exmple code 4)wht is Singleton and code for singleton class... ( asked if i know other design patterens, i said no :) 5)what is thread, diff b/w process and thread, ways of interprocess communication 6)Inside the constructer of the class, assume memory is allocated using new at 2nd line and exception is thrown in next line, once the exception is handled, will we have the access to the memory allocated at 2nd line ? If yes how? if no how do we handle memory leak ? (I was confused and my ans was smart pointers, still not sure wht is the ans) 7)Write a code to depict virtual function and explain how virtual pointer works ? How many vptr's and v'tables will be there? 8) Deep copy v/s shallow copy. Copy cons and assignment operstpor 9)Operator overloading 10) ref v/s pointers 11)Virtul base clsss 12)c++ code to find the pos of a given chrcter in string and print the "remaining string starting from tht position/charcter" 13)Placement new