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


220. All deallocation functions should be required not to throw

Section: 6.7.5.5.3  [basic.stc.dynamic.deallocation]     Status: CD1     Submitter: Herb Sutter     Date: 31 Mar 2000

[Voted into the WP at the September, 2008 meeting (resolution in paper N2757).]

[Picked up by evolution group at October 2002 meeting.]

The default global operators delete are specified to not throw, but there is no requirement that replacement global, or class-specific, operators delete must not throw. That ought to be required.

In particular:

We already require that all versions of an allocator's deallocate() must not throw, so that part is okay.

Rationale (04/00):

  1. Replacement deallocation functions are already required not to throw an exception (cf 16.4.5.8 [res.on.functions] paragraph 2, as applied to 17.6.3.2 [new.delete.single] paragraph 12 and 17.6.3.3 [new.delete.array] paragraph 11).
  2. Section 16.4.5.6 [replacement.functions] is describing the signatures of the functions to be replaced; exception specfications are not part of the signature.
  3. There does not appear to be any pressing need to require that class member deallocation functions not throw.

Note (March, 2008):

The Evolution Working Group has accepted the intent of this issue and referred it to CWG for action for C++0x (see paper J16/07-0033 = WG21 N2173).

Proposed resolution (March, 2008):

Change 6.7.5.5.3 [basic.stc.dynamic.deallocation] paragraph 3 as follows:

A deallocation function shall not terminate by throwing an exception. The value of the first argument supplied to a deallocation function...