I think what he meant was objects being destroyed implicitly when they go out of scope - some kind of a "controlled" automatic garbage collection. And it's true that this particular feature in C++ has led to creation of many interesting techniques - auto-pointer, scope locking, to name a few - that otherwise would require full support on the compiler side. The beauty of C++ is that you can implement this kind of things yourself without changing the language.
A: The C++ destructor and the programming techniques that rely on it.
"C++ destructor": Java/Python/etc.?