This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 120b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2026-07-26

3165. Use "equivalent type" to support templated entities

(From submission #860.)

Subclause 6.7 [basic.link] bullet 11.1 applies to all functions and variables, including templated ones, thus can involve dependent types for which "same type" is not defined.

Proposed resolution (approved by CWG 2026-05-08):

Change in 6.7 [basic.link] bullet 11.1 as follows:

For any two declarations of an entity E:

• If one declares E to be a (possibly templated) variable or function, the other shall declare E as one of the same equivalent type (13.7.7.2 [temp.over.link]).
• ...
• If one declares E to be a class template, the other shall do so with the same kind and an equivalent template-head (13.7.7.2 [temp.over.link]).
• ...

CWG 2026-06-10

It is believed that 13.7.7.2 [temp.over.link] or 13.6 [temp.type] should define "same type" to be applicable for dependent types, too. See issue 2584 for the missing definition.