[Boost-bugs] [Boost C++ Libraries] #3643: Auto type deduction in 'foreach'

Subject: [Boost-bugs] [Boost C++ Libraries] #3643: Auto type deduction in 'foreach'
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-11-19 11:22:23

#3643: Auto type deduction in 'foreach'
--------------------------------+-------------------------------------------
 Reporter:  akrzemi1@…          |       Owner:  eric_niebler
     Type:  Feature Requests    |      Status:  new         
Milestone:  Boost 1.42.0        |   Component:  foreach     
  Version:  Boost 1.41.0        |    Severity:  Problem     
 Keywords:                      |  
--------------------------------+-------------------------------------------
 I would like to request a new tool in Boost.Foreach that
 would emulate the following C++0x construct:

   for( auto const& x : collection ) { ... }

 It would look something like:

   BOOST_FOREACH_AUTO( const& x, collection ) {...}

 To prove it is doable I enclose the following suboptimal implementation as
 a proof of concept. It was already pointed out that the faster
 implementation is possible.

 #define BOOST_FOREACH_AUTO( INIT, CONT ) \
   BOOST_FOREACH(   \
     BOOST_TYPEOF( *boost::begin(CONT) ) INIT, \
     CONT  \
   )

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3643>
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