This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See for the official list.


1519. Conflicting default and variadic constructors

Section: 13.7.4  [temp.variadic]     Status: NAD     Submitter: Ville Voutilainen     Date: 2012-07-09

A specialization of a variadic function template can produce the same function signature as a non-variadic one; in particular, a class can end up with multiple default constructors if a pack expansion is empty. It would be helpful if such a specialization could be suppressed so that the non-variadic function were preferred.

Rationale (October, 2012):

It can be argued that this is not a defect in the language but simply something that must be considered by the programmer: if the default constructor and the empty-pack-expansion constructor do the same thing, the default constructor is superfluous, while if they do different things there may be a logic error in one or the other. EWG should resolve the policy question of whether this situation should receive special treatment in the language to make it well-formed.

Rationale (February, 2014):

EWG determined that no action should be taken on this issue. There is an existing workaround for the problem, and it will also be addressed by the Concepts Lite proposal.