destructors should be simple.. really?

This is typical of c++ -- destructor (dtor) is one of the most important features but quite tricky beneath the surface

* exception
* dtor sequence - DCBC
* virtual dtor
* synthesized dtor is usually no good if there's any pointer field
* lots of undefined behaviors
* there are guidelines for dtor in a base class vs leaf class -- never mindless
* objects put into containers need a reasonable dtor
* when the best practice is to leave the dtor to the compiler, you could look stupid by writing one, esp. in an interview.
* smart pointer classes is all about dtor
* RAII is all about dtor

* interplay with delete
*** placement new, array-delete vs delete
*** override operator delete
*** double-delete
*** ownership !