//----------------------------------------------------------------------------- // boost mpl/example/integer.cpp source file // See http://www.boost.org for updates, documentation, and revision history. //----------------------------------------------------------------------------- // // Copyright (c) 2001-02 // Aleksey Gurtovoy // // Permission to use, copy, modify, distribute and sell this software // and its documentation for any purpose is hereby granted without fee, // provided that the above copyright notice appears in all copies and // that both the copyright notice and this permission notice appear in // supporting documentation. No representations are made about the // suitability of this software for any purpose. It is provided "as is" // without express or implied warranty. #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/apply_if.hpp" #include "boost/mpl/apply.hpp" #include "boost/mpl/begin_end.hpp" #include "boost/mpl/assert_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 builtins_; typedef typename mpl::base< typename mpl::lower_bound< mpl::transform_view< builtins_ , mpl::multiplies< mpl::sizeof_<_1>, mpl::int_<8> > > , mpl::int_ >::type >::type iter_; typedef typename mpl::end::type last_; typedef typename mpl::apply_if< boost::is_same , mpl::identity< big_int > , mpl::apply0 >::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_IS_SAME(int1, char); BOOST_MPL_ASSERT_IS_SAME(int5, char); BOOST_MPL_ASSERT_IS_SAME(int15, short); BOOST_MPL_ASSERT_IS_SAME(int32, int); BOOST_MPL_ASSERT_IS_SAME(int100, big_int<100>);