text: // Copyright Daniel Wallin, David Abrahams 2005. Use, modification and
  // distribution is subject to the Boost Software License, Version 1.0. (See
  // accompanying file LICENSE_1_0.txt or copy at
  // http://www.boost.org/LICENSE_1_0.txt)
  
  #ifndef YESNO_050328_HPP
  #define YESNO_050328_HPP
  
  #include <boost/mpl/bool.hpp>
  
  namespace boost { namespace parameter { namespace aux {
  
  // types used with the "sizeof trick" to capture the results of
  // overload resolution at compile-time.
  typedef char yes_tag;
  typedef char (&no_tag)[2];
  
  // mpl::true_ and mpl::false_ are not distinguishable by sizeof(),
  // so we pass them through these functions to get a type that is.
  yes_tag to_yesno(mpl::true_);
  no_tag to_yesno(mpl::false_);
  
  }}} // namespace boost::parameter::aux
  
  #endif // YESNO_050328_HPP
  
  