http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55043
--- Comment #12 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2012-10-24 08:33:47 UTC --- (In reply to comment #11) > That seems inconsistent with 20.9.4.3/6 > > the predicate condition for a template specialization is_constructible<T, > Args...> shall be satisfied if and only if the following variable definition > would be well-formed for some invented variable t: > T t(create<Args>()...); > > and that variable definition is not well-formed: > > const N<M>& create(); > N<M> t(create()); I think this is covered by that wording, which was added very late to ensure that only the immediate context is relevant: "Only the validity of the immediate context of the variable initialization is considered. [ Note: The evaluation of the initialization can result in side effects such as the instantiation of class template specializations and function template specializations, the generation of implicitly-defined functions, and so on. Such side effects are not in the “immediate context” and can result in the program being ill-formed. —end note ]
