Closed
Description
The Constructible utility currently supports only types that provide a constructor, which is not the case for references. However, since Constructible is used as underlying mechanism for Unique_attempt, references cannot be returned as Unique_attempt objects. This is unfortunate for implementing factories (e.g., stack allocation in base/thread.h) that are forced to use a pointer type instead of a reference. To remove the need for such workarounds, Constructible should best support reference types in the first place.