// (C) Copyright David Abrahams 2001.

// Distributed under 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)

//

// See http://www.boost.org for most recent version including documentation.

// Revision History

// 09 Feb 01  Applied John Maddock's Borland patch Moving <true>

//            specialization to unspecialized template (David Abrahams)

// 06 Feb 01  Created (David Abrahams)

#ifndef SELECT_TYPE_DWA20010206_HPP

# define SELECT_TYPE_DWA20010206_HPP

namespace boost { namespace detail {

  // Template class if_true -- select among 2 types based on a bool constant expression

  // Usage:

  //   typename if_true<(bool_const_expression)>::template then<true_type, false_type>::type

  // HP aCC cannot deal with missing names for template value parameters

  template <bool b> struct if_true

  {

      template <class T, class F>

      struct then { typedef T type; };

  };

  template <>

  struct if_true<false>

  {

      template <class T, class F>

      struct then { typedef F type; };

  };

}}

#endif // SELECT_TYPE_DWA20010206_HPP