This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 110b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2023-01-15


2605. Implicit-lifetime aggregates

Section: 11.2  [class.prop]     Status: DR     Submitter: Davis Herring     Date: 2022-06-27

[Accepted as a DR at the November, 2022 meeting.]

Subclause 11.2 [class.prop] paragraph 9 specifies:

A class S is an implicit-lifetime class if

However, an aggregate may have a non-deleted non-trivial destructor:

  struct X {
    Y i;
    ~X();
  };

This class is an aggregate, but destroying X itself (ignoring the subobjects) does not satisfy "destroying an instance of the type runs no code"; see P0593R6 "Implicit creation of objects for low-level object manipulation" section 3.1.

Additional notes (September, 2022):

From a thread starting here: What if X had a deleted destructor (either explicitly or implicitly)?

CWG 2022-11-09:

A deleted destructor does not prevent an aggregate from being an implicit-lifetime class.

Proposed resolution (approved by CWG 2022-11-09):

Change in 11.2 [class.prop] paragraph 9 as follows:

A class S is an implicit-lifetime class if