//  boost integer.hpp header file  -------------------------------------------//

 //  Copyright Beman Dawes and Daryle Walker 1999.  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/integer for documentation.

 //  Revision History

 //   22 Sep 01  Added value-based integer templates. (Daryle Walker)

 //   01 Apr 01  Modified to use new <boost/limits.hpp> header. (John Maddock)

 //   30 Jul 00  Add typename syntax fix (Jens Maurer)

 //   28 Aug 99  Initial version

 #ifndef BOOST_INTEGER_HPP

 #define BOOST_INTEGER_HPP

 #include <boost/integer_fwd.hpp>  // self include

 #include <boost/integer_traits.hpp>  // for boost::integer_traits

 #include <boost/limits.hpp>          // for std::numeric_limits

 namespace boost

 {

   //  Helper templates  ------------------------------------------------------//

   //  fast integers from least integers

   //  int_fast_t<> works correctly for unsigned too, in spite of the name.

   template< typename LeastInt >

   struct int_fast_t { typedef LeastInt fast; }; // imps may specialize

   //  convert category to type 

   template< int Category > struct int_least_helper {}; // default is empty

   //  specializatons: 1=long, 2=int, 3=short, 4=signed char,

   //     6=unsigned long, 7=unsigned int, 8=unsigned short, 9=unsigned long

   //  no specializations for 0 and 5: requests for a type > long are in error

   template<> struct int_least_helper<1> { typedef long least; };

   template<> struct int_least_helper<2> { typedef int least; };

   template<> struct int_least_helper<3> { typedef short least; };

   template<> struct int_least_helper<4> { typedef signed char least; };

   template<> struct int_least_helper<6> { typedef unsigned long least; };

   template<> struct int_least_helper<7> { typedef unsigned int least; };

   template<> struct int_least_helper<8> { typedef unsigned short least; };

   template<> struct int_least_helper<9> { typedef unsigned char least; };

   //  integer templates specifying number of bits  ---------------------------//

   //  signed

   template< int Bits >   // bits (including sign) required

   struct int_t 

   {

       typedef typename int_least_helper

         <

           (Bits-1 <= std::numeric_limits<long>::digits) +

           (Bits-1 <= std::numeric_limits<int>::digits) +

           (Bits-1 <= std::numeric_limits<short>::digits) +

           (Bits-1 <= std::numeric_limits<signed char>::digits)

         >::least  least;

       typedef typename int_fast_t<least>::fast  fast;

   };

   //  unsigned

   template< int Bits >   // bits required

   struct uint_t 

   {

       typedef typename int_least_helper

         < 

           5 +

           (Bits <= std::numeric_limits<unsigned long>::digits) +

           (Bits <= std::numeric_limits<unsigned int>::digits) +

           (Bits <= std::numeric_limits<unsigned short>::digits) +

           (Bits <= std::numeric_limits<unsigned char>::digits)

         >::least  least;

       typedef typename int_fast_t<least>::fast  fast;

       // int_fast_t<> works correctly for unsigned too, in spite of the name.

   };

   //  integer templates specifying extreme value  ----------------------------//

   //  signed

   template< long MaxValue >   // maximum value to require support

   struct int_max_value_t 

   {

       typedef typename int_least_helper

         <

           (MaxValue <= integer_traits<long>::const_max) +

           (MaxValue <= integer_traits<int>::const_max) +

           (MaxValue <= integer_traits<short>::const_max) +

           (MaxValue <= integer_traits<signed char>::const_max)

         >::least  least;

       typedef typename int_fast_t<least>::fast  fast;

   };

   template< long MinValue >   // minimum value to require support

   struct int_min_value_t 

   {

       typedef typename int_least_helper

         <

           (MinValue >= integer_traits<long>::const_min) +

           (MinValue >= integer_traits<int>::const_min) +

           (MinValue >= integer_traits<short>::const_min) +

           (MinValue >= integer_traits<signed char>::const_min)

         >::least  least;

       typedef typename int_fast_t<least>::fast  fast;

   };

   //  unsigned

   template< unsigned long Value >   // maximum value to require support

   struct uint_value_t 

   {

       typedef typename int_least_helper

         < 

           5 +

           (Value <= integer_traits<unsigned long>::const_max) +

           (Value <= integer_traits<unsigned int>::const_max) +

           (Value <= integer_traits<unsigned short>::const_max) +

           (Value <= integer_traits<unsigned char>::const_max)

         >::least  least;

       typedef typename int_fast_t<least>::fast  fast;

   };

 } // namespace boost

 #endif  // BOOST_INTEGER_HPP