From: lichray@googlemail.com   
      
   On Thursday, 22/11/2012 1:46:09 AM UTC-6, Frank Birbacher wrote:   
   > Does to following code reliably construct a pair that holds a given   
   > value twice? Is it true that pair::first will be constructed before   
   > pair::second? Does make_pair only forward arguments?   
      
   No.  Actually, It copies its argument first, then copies t and move t   
   into make_pair's argument list, in an indeterminate sequence.  The   
   moving /b/ can happen before the copying /a/.   
      
   > template   
   > std::pair fanout(T t)   
   > {   
   >   return std::make_pair(t, std::move(t));   
                             /a/ /b/   
      
   If you cares the initialization ordering, you can consider an   
   std::array:   
      
   template   
   std::array fanout2(T const& t)   
   {   
      return { t, t };   
   }   
      
      
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