This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-12-19


2024. Dependent types and unexpanded parameter packs

Section: 13.8.3.2  [temp.dep.type]     Status: CD4     Submitter: Richard Smith     Date: 2014-10-17

[Moved to DR at the October, 2015 meeting.]

Consider an example like:

  template<typename ...Ts> struct X { X(int); };
  template<typename T> using Y = int;
  template<typename ...Ts> void f() {
    X<Y<Ts>...> x;
  }

The presence of the ellipsis should make the reference to X a dependent type, but there is no rule making it so.

Proposed resolution (May, 2015):

Change 13.8.3.2 [temp.dep.type] paragraph 9 as follows:

A type is dependent if it is