//  tuple_ignore.hpp -----------------------------------------------------

// Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
//
// Permission to copy, use, sell and distribute this software is granted
// provided this copyright notice appears in all copies.
// Permission to modify the code and to distribute modified code is granted
// provided this copyright notice appears in all copies, and a notice
// that the code was modified is included with the copyright notice.
//
// This software is provided "as is" without express or implied warranty,
// and with no claim as to its suitability for any purpose.

// For more information, see http://www.boost.org

// -----------------------------------------------------------------

#ifndef BOOST_TUPLE_IGNORE_HPP
#define BOOST_TUPLE_IGNORE_HPP

namespace boost {
namespace tuples {


// Swallows any assignment   (by Doug Gregor)
namespace detail {

struct swallow_assign {

  template<typename T>
  swallow_assign& operator=(const T&) {
    return *this;
  }
};

} // namespace detail

// "ignore" allows tuple positions to be ignored when using "tie".

#ifdef BOOST_TUPLE_EXTERN
#  ifndef BOOST_TUPLE_EXTERN_DEFINITION
#    define BOOST_TUPLE_LINKAGE  extern
#  else
#    define BOOST_TUPLE_LINKAGE 
#  endif
#  define BOOST_TUPLE_DECLSPEC BOOST_DECL
#else
#  define BOOST_TUPLE_LINKAGE
#  define BOOST_TUPLE_DECLSPEC
#endif

#ifndef BOOST_TUPLE_EXTERN 
namespace {
#endif

BOOST_TUPLE_LINKAGE detail::swallow_assign BOOST_TUPLE_DECLSPEC ignore;

#ifndef BOOST_TUPLE_EXTERN
} // unnamed namespace
#endif

} // end of namespace tuples
} // end of namespace boost

#undef BOOST_TUPLE_LINKAGE
#undef BOOST_TUPLE_DECLSPEC

#endif	// BOOST_TUPLE_IGNORE_HPP