id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
3114,Modified interface to allow even lazier return types for defaults,Jeremiah Willcock,Jeremiah Willcock,"There are some use cases where the return type of operator() in a default computation class is not valid in some cases when that default is not used.  The current interface to such classes does not allow that case; see the message at http://lists.boost.org/Archives/boost/2009/05/152009.php for more information.  The attached patch allows a special member type (that must be void) to be used to change the interface to pass a single int argument to operator(), while keeping the old no-parameter interface for function objects without the special tag.  The tag could also have been implemented as a traits class used with enable_if.  The patch passes all of the Boost.Parameter tests except two (which appear to freeze up).  I only changed the normal path through the code, and not the compatibility code which I am unable to test.  A test for the new functionality added by the patch is also attached.",Feature Requests,new,Boost 1.42.0,parameter,Boost 1.38.0,Problem,,,