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This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 119a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-12-20

2428. Deprecating a concept

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

The grammar for aconcept-definition does not include anattribute-specifier-seq_opt, making it impossibleto deprecate a concept. This seems like an oversight.

CWG telecon 2022-10-07:

Agreed.

Proposed resolution (approved by CWG 2022-10-21):

1. Change in 9.13.4 [dcl.attr.deprecated] paragraph 2 as follows:

   The attribute may be applied to the declaration of a class,atypedef-name, a variable, a non-static data member, afunction, a namespace, an enumeration, an enumerator,a concept, or a template specialization.

2. Change in 13.7.9 [temp.concept] paragraph 1 as follows:

   A concept is a template that defines constraints on its templatearguments.

   concept-definition:    conceptconcept-nameattribute-specifier-seqopt =constraint-expression ;concept-name:identifier

   Aconcept-definition declares a concept. Itsidentifierbecomes aconcept-name referring to that concept within itsscope.The optionalattribute-specifier-seq appertains tothe concept.