When passing a class by-value, does the caller or callee call the destructor?

Question

Suppose that I have the following (trimmed down) code:

class P { P(); P(const P&); ~P(); }

void foo(P x) {
  ...
}

         


        

Answer 1

The standard answers this question in [expr.call]/4, with a surprising amount of elaboration:

... The initialization and destruction of each parameter occurs within the context of the calling function. [ Example: The access of the constructor, conversion functions or destructor is checked at the point of call in the calling function. If a constructor or destructor for a function parameter throws an exception, the search for a handler starts in the scope of the calling function; in particular, if the function called has a function-try-block (Clause 18) with a handler that could handle the exception, this handler is not considered. —end example ]

In other words, the destructor is invoked by the calling function.