Hello, Here's boost/aux_/void.hpp contents, without include quards and license note, where I marked a line with a comment to refer to it below. [code] namespace boost { namespace parameter { // A placemarker for "no argument passed." // MAINTAINER NOTE: Do not make this into a metafunction struct void_ {}; namespace aux { inline void_& void_reference() { static void_ instance; // (1) return instance; } } // namespace aux }} // namespace boost::parameter [/code] My question is: is it allowed to use an instance of an uninitialized empty struct? The struct void_ is empty. On line (1) a static uninitialized instance of struct void_ is defined, and it is then returned. Does the standard allow this? I can't imagine any real problems with this, but I'm curious if this has defined behavior according to the standard. A natural and simple solution to my concern is of course to change the line (1) to: static void_ instance = {}; I'd be happy to create a ticket with a patch, if my concern is valid. Regards, Kris