[Boost-bugs] [Boost C++ Libraries] #6091: Not documented requirement about I/O operators

Subject: [Boost-bugs] [Boost C++ Libraries] #6091: Not documented requirement about I/O operators
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-11-03 21:26:18

#6091: Not documented requirement about I/O operators
------------------------------+---------------------------------------------
 Reporter:  mloskot           |       Owner:         
     Type:  Bugs              |      Status:  new    
Milestone:  To Be Determined  |   Component:  None   
  Version:  Boost 1.47.0      |    Severity:  Problem
 Keywords:                    |  
------------------------------+---------------------------------------------
 The Fusion documentation in Boost 1.47 does not mention that in order to
 make Fusion-adapted types usable with input and output operators, it is
 necessary to import these operators into type's namespace.

 The problem is discussed in the thread [http://lists.boost.org/boost-

 users/2011/11/71518.php Adapted struct I/O].

 Here is sample based on the
 [http://www.boost.org/doc/libs/1_47_0/libs/fusion/doc/html/fusion/adapted/adapt_tpl_struct.html

 demo::employee] example that shows correct use of Fusion-adapted type:

 {{{
 #include <iostream>
 #include <string>
 #include <boost/fusion/adapted/struct/adapt_struct.hpp>
 #include <boost/fusion/include/adapt_struct.hpp>
 #include <boost/fusion/sequence/io.hpp>
 #include <boost/fusion/include/io.hpp>

 namespace demo
 {
     // This does the trick, but not documented
     using boost::fusion::operators::operator<<;
     using boost::fusion::operators::operator>>;


     template<typename Name, typename Age>
     struct employee
     {
         Name name;
         Age age;
     };
 }

 // Any instantiated demo::employee is now a Fusion sequence
 BOOST_FUSION_ADAPT_TPL_STRUCT(
     (Name)(Age),
     (demo::employee) (Name)(Age),
     (Name, name)
     (Age, age))

 int main()
 {
     demo::employee<std::string, int> e;
     std::cin >> e;
     std::cout << e << std::endl;
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6091>
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