[Boost-bugs] [Boost C++ Libraries] #2103: ostream::operator<<(bool) is called if optional_io.hpp is not included

Subject: [Boost-bugs] [Boost C++ Libraries] #2103: ostream::operator<<(bool) is called if optional_io.hpp is not included
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-07-10 10:44:05

#2103: ostream::operator<<(bool) is called if optional_io.hpp is not included
--------------------------+-------------------------------------------------
 Reporter:  nasonov       |       Owner:  fcacciola
     Type:  Bugs          |      Status:  new      
Milestone:  Boost 1.36.0  |   Component:  optional 
  Version:  Boost 1.35.0  |    Severity:  Problem  
 Keywords:                |  
--------------------------+-------------------------------------------------
 If you pass an optional<T> value to ostream, it would print a result of
 safe_bool() if <boost/optional/optional_io.hpp> is not included.
 {{{
 $ cat -n unspecified_bool_type.cpp
      1  #include <iostream>
      2  #include <boost/optional/optional.hpp>
      3
      4  boost::optional<char> o('o');
      5
      6  void without_io()
      7  {
      8    std::cout << o << '\n';
      9  }
     10
     11  #include <boost/optional/optional_io.hpp>
     12
     13  void with_io()
     14  {
     15    std::cout << o << '\n';
     16  }
     17
     18  int main()
     19  {
     20    without_io();
     21    with_io();
     22  }
 $ ./a.out
 1
  o
 }}}
 This can be fixed by a adding forward declaration of operator<< to
 optional_fwd.hpp.

 Note that other uses of unspecified_bool_type may be buggy.

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/2103>
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