Re: [Boost-bugs] [Boost C++ Libraries] #7276: Add move semantics

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7276: Add move semantics
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-02-26 21:40:35

#7276: Add move semantics
-------------------------------+--------------------------------------------
  Reporter:  viboes            |       Owner:  djowel 
      Type:  Feature Requests  |      Status:  new    
 Milestone:  To Be Determined  |   Component:  tuple  
   Version:  Boost 1.51.0      |    Severity:  Problem
Resolution:                    |    Keywords:         
-------------------------------+--------------------------------------------

Comment (by awulkiew):

 I've created experimental version of tuple supporting move-semantics here:

 http://svn.boost.org/svn/boost/sandbox/tuple-move/


 To ensure backward compatibility I've defined copy assignment explicitly.
 It's possible to use tuples wrapped in classes with implicit assignment
 operator in c++03:

 {{{
 struct wrapper
 {
   tuple<int> t;
 };
 /*...*/
 wrapper w;
 w = wrapper();
 }}}

 however in c++03 move assignment won't be used if tuple is returned from a
 function by value.

 {{{
 tuple<int> ret_tup(int a) { return tuple<int>(a); }
 /*...*/
 tuple<int> t;
 t = ret_tup(0); // copy in c++03
 }}}

 We could add a define check that disables mentioned explicit copy
 assignments. Defining it would enable moving of objects returned by value
 but prevent compilation of wrappers with implicit copy assignment.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7276#comment:1>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.