Re: [Boost-bugs] [Boost C++ Libraries] #1404: Unordered Fusion Map constructors.

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #1404: Unordered Fusion Map constructors.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-05-28 17:48:35

#1404: Unordered Fusion Map constructors.
-----------------------------------------------------------+----------------
  Reporter:  Dean Michael Berris <mikhailberis_at_[hidden]>  |       Owner:  djowel  
      Type:  Feature Requests                              |      Status:  new     
 Milestone:  To Be Determined                              |   Component:  fusion  
   Version:  Boost Development Trunk                       |    Severity:  Cosmetic
Resolution:                                                |    Keywords:          
-----------------------------------------------------------+----------------

Comment(by srajko):

 [Bug Sprint] One way I see of implementing this would be through a view
 which reorders the elements of a source map to match the order of keys of
 a target map.  This view could then be used for construction and
 assignment from an existing map:

 {{{

 my_map_type instance (
   reorder_map_to<my_map_type> (
     make_map( make_pair<tags::type_2>(2), make_pair<tags::type_1>(1) ) )
 );

 instance =
   reorder_map_to<my_map_type> (
     make_map( make_pair<tags::type_2>(2), make_pair<tags::type_1>(1) ) )
 );

 // or

 my_map_type instance ( reorder_map_to<my_map_type> (some_other_map) );

 instance = reorder_map_to<my_map_type> (some_other_map);

 }}}

 The map class could use the reordering view automatically in construction
 from a list of arguments, construction from a Sequence, and assignment (so
 that the OP's original code snippet compiles), but that would complicate
 the otherwise simple implementation.  Would using the reordering view
 manually fulfill the need here?

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/1404#comment:1>
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