http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53162
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-30 08:12:44 UTC --- (In reply to comment #0) > The declaration of f1 is rejected but with an unhelpful diagnostic, if the ^^ That should say: f2 I believe the errors should be given when the constructor templates are defined, rather than at instantiation, because "An appearance of a name of a parameter pack that is not expanded is ill-formed." (14.5.3 [temp.variadic] p5)