[Boost-bugs] [Boost C++ Libraries] #4189: Add better support for non-default constructible function objects

Subject: [Boost-bugs] [Boost C++ Libraries] #4189: Add better support for non-default constructible function objects
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-05-04 22:43:03

#4189: Add better support for non-default constructible function objects
--------------------------------+-------------------------------------------
 Reporter:  djwalker            |       Owner:  dave    
     Type:  Feature Requests    |      Status:  new     
Milestone:  Boost 1.43.0        |   Component:  iterator
  Version:  Boost 1.42.0        |    Severity:  Problem 
 Keywords:  transform_iterator  |  
--------------------------------+-------------------------------------------
 boost::transform_iterator is required to be default constructible, but not
 all function objects are. For example, boost::mem_fn_t is not default
 constructible. To allow transform_iterator to model DefaultConstructible
 with any function object type, Peter Dimov suggested using
 boost::optional. Thanks to Samuel Debionne for identifying and reporting
 the problem.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/4189>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.