| |
| // Copyright Aleksey Gurtovoy 2001-2004 |
| // |
| // 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/libs/mpl for documentation. |
| |
| // $Id: integer.cpp 49268 2008-10-11 06:26:17Z agurtovoy $ |
| // $Date: 2008-10-11 02:26:17 -0400 (Sat, 11 Oct 2008) $ |
| // $Revision: 49268 $ |
| |
| #include <boost/mpl/multiplies.hpp> |
| #include <boost/mpl/list.hpp> |
| #include <boost/mpl/lower_bound.hpp> |
| #include <boost/mpl/transform_view.hpp> |
| #include <boost/mpl/sizeof.hpp> |
| #include <boost/mpl/int.hpp> |
| #include <boost/mpl/identity.hpp> |
| #include <boost/mpl/base.hpp> |
| #include <boost/mpl/eval_if.hpp> |
| #include <boost/mpl/deref.hpp> |
| #include <boost/mpl/begin_end.hpp> |
| #include <boost/mpl/assert.hpp> |
| |
| #include <boost/type_traits/is_same.hpp> |
| |
| namespace mpl = boost::mpl; |
| using namespace mpl::placeholders; |
| |
| template< int bit_size > |
| class big_int |
| { |
| // ... |
| }; |
| |
| template< int bit_size > |
| struct integer |
| { |
| typedef mpl::list<char,short,int,long> builtins_; |
| typedef typename mpl::base< typename mpl::lower_bound< |
| mpl::transform_view< builtins_ |
| , mpl::multiplies< mpl::sizeof_<_1>, mpl::int_<8> > |
| > |
| , mpl::int_<bit_size> |
| >::type >::type iter_; |
| |
| typedef typename mpl::end<builtins_>::type last_; |
| typedef typename mpl::eval_if< |
| boost::is_same<iter_,last_> |
| , mpl::identity< big_int<bit_size> > |
| , mpl::deref<iter_> |
| >::type type; |
| }; |
| |
| typedef integer<1>::type int1; |
| typedef integer<5>::type int5; |
| typedef integer<15>::type int15; |
| typedef integer<32>::type int32; |
| typedef integer<100>::type int100; |
| |
| BOOST_MPL_ASSERT(( boost::is_same< int1, char > )); |
| BOOST_MPL_ASSERT(( boost::is_same< int5, char > )); |
| BOOST_MPL_ASSERT(( boost::is_same< int15, short > )); |
| BOOST_MPL_ASSERT(( boost::is_same< int32, int > )); |
| BOOST_MPL_ASSERT(( boost::is_same< int100, big_int<100> > )); |