boost/pending/ct_if.hpp

   1 // (C) Copyright Jeremy Siek 2000.
   2 // Distributed under the Boost Software License, Version 1.0. (See
   3 // accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5
   6 // This header replaces the implementation of ct_if that preceded the
   7 // introduction of Boost.MPL with a facade that defers to that reviewed and
   8 // accepted library.
   9
  10 // Author: Ronald Garcia
  11 // Date: 20 October, 2006
  12
  13
  14 #ifndef BOOST_CT_IF_HPP
  15 #define BOOST_CT_IF_HPP
  16
  17
  18 // A stub implementation in terms of Boost.MPL
  19
  20 #include <boost/mpl/if.hpp>
  21 #include <boost/mpl/not.hpp>
  22 #include <boost/mpl/and.hpp>
  23 // true_type and false_type are used by applications of ct_if
  24 #include <boost/type_traits/integral_constant.hpp>
  25
  26 namespace boost {
  27
  28   template <class A, class B>
  29   struct ct_and : boost::mpl::and_<A,B> {};
  30
  31   template <class A>
  32   struct ct_not : mpl::not_<A> {};
  33
  34   template <bool cond, class A, class B>
  35   struct ct_if : mpl::if_c<cond,A,B> {};
  36
  37   template <class cond, class A, class B>
  38   struct ct_if_t : mpl::if_<cond,A,B> {};
  39
  40 } // namespace boost
  41
  42 #endif // BOOST_CT_IF_HPP
  43