This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 114b. See for the official list.


2695. Semantic ignorability of attributes

Section: 9.12.1  [dcl.attr.grammar]     Status: C++23     Submitter: Timur Doumler     Date: 2023-02-09

[Accepted as a DR at the February, 2023 meeting.]

EWG resolved to reflect the understanding of semantic ignorability of attributes in a note.

Proposed resolution (approved by CWG 2023-02-09):

Add to 9.12.1 [dcl.attr.grammar] paragraph 6 as follows:

[Note 4: A program is ill-formed if it contains an attribute specified in 9.12 [dcl.attr] that violates the rules specifying to which entity or statement the attribute can apply or the syntax rules for the attribute's attribute-argument-clause, if any. —end note] [Note: The attributes specified in 9.12 [dcl.attr] have optional semantics: given a well-formed program, removing all instances of any one of those attributes results in a program whose set of possible executions (4.1.2 [intro.abstract]) for a given input is a subset of those of the original program for the same input, absent implementation-defined guarantees with respect to that attribute. -- end note ]