Item 40. Object Lifetimes桺art 1

Difficulty: 5

"To be, or not to be…" When does an object actually exist? This problem considers when an object is safe to use.

Critique the following code fragment.

void f() 


{


  T t(1);


  T& rt = t;


  //--- #1: do something with t or rt ---


  t.~T();


  new (&t) T(2);


  //--- #2: do something with t or rt ---


}// t is destroyed again

Is the code in block #2 safe and/or legal? Explain.