williamr@2: //  boost integer.hpp header file  -------------------------------------------//
williamr@2: 
williamr@2: //  Copyright Beman Dawes and Daryle Walker 1999.  Distributed under the Boost
williamr@2: //  Software License, Version 1.0. (See accompanying file
williamr@2: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
williamr@2: 
williamr@2: //  See http://www.boost.org/libs/integer for documentation.
williamr@2: 
williamr@2: //  Revision History
williamr@2: //   22 Sep 01  Added value-based integer templates. (Daryle Walker)
williamr@2: //   01 Apr 01  Modified to use new <boost/limits.hpp> header. (John Maddock)
williamr@2: //   30 Jul 00  Add typename syntax fix (Jens Maurer)
williamr@2: //   28 Aug 99  Initial version
williamr@2: 
williamr@2: #ifndef BOOST_INTEGER_HPP
williamr@2: #define BOOST_INTEGER_HPP
williamr@2: 
williamr@2: #include <boost/integer_fwd.hpp>  // self include
williamr@2: 
williamr@2: #include <boost/integer_traits.hpp>  // for boost::integer_traits
williamr@2: #include <boost/limits.hpp>          // for std::numeric_limits
williamr@2: 
williamr@2: namespace boost
williamr@2: {
williamr@2: 
williamr@2:   //  Helper templates  ------------------------------------------------------//
williamr@2: 
williamr@2:   //  fast integers from least integers
williamr@2:   //  int_fast_t<> works correctly for unsigned too, in spite of the name.
williamr@2:   template< typename LeastInt >
williamr@2:   struct int_fast_t { typedef LeastInt fast; }; // imps may specialize
williamr@2: 
williamr@2:   //  convert category to type 
williamr@2:   template< int Category > struct int_least_helper {}; // default is empty
williamr@2: 
williamr@2:   //  specializatons: 1=long, 2=int, 3=short, 4=signed char,
williamr@2:   //     6=unsigned long, 7=unsigned int, 8=unsigned short, 9=unsigned long
williamr@2:   //  no specializations for 0 and 5: requests for a type > long are in error
williamr@2:   template<> struct int_least_helper<1> { typedef long least; };
williamr@2:   template<> struct int_least_helper<2> { typedef int least; };
williamr@2:   template<> struct int_least_helper<3> { typedef short least; };
williamr@2:   template<> struct int_least_helper<4> { typedef signed char least; };
williamr@2:   template<> struct int_least_helper<6> { typedef unsigned long least; };
williamr@2:   template<> struct int_least_helper<7> { typedef unsigned int least; };
williamr@2:   template<> struct int_least_helper<8> { typedef unsigned short least; };
williamr@2:   template<> struct int_least_helper<9> { typedef unsigned char least; };
williamr@2: 
williamr@2:   //  integer templates specifying number of bits  ---------------------------//
williamr@2: 
williamr@2:   //  signed
williamr@2:   template< int Bits >   // bits (including sign) required
williamr@2:   struct int_t 
williamr@2:   {
williamr@2:       typedef typename int_least_helper
williamr@2:         <
williamr@2:           (Bits-1 <= std::numeric_limits<long>::digits) +
williamr@2:           (Bits-1 <= std::numeric_limits<int>::digits) +
williamr@2:           (Bits-1 <= std::numeric_limits<short>::digits) +
williamr@2:           (Bits-1 <= std::numeric_limits<signed char>::digits)
williamr@2:         >::least  least;
williamr@2:       typedef typename int_fast_t<least>::fast  fast;
williamr@2:   };
williamr@2: 
williamr@2:   //  unsigned
williamr@2:   template< int Bits >   // bits required
williamr@2:   struct uint_t 
williamr@2:   {
williamr@2:       typedef typename int_least_helper
williamr@2:         < 
williamr@2:           5 +
williamr@2:           (Bits <= std::numeric_limits<unsigned long>::digits) +
williamr@2:           (Bits <= std::numeric_limits<unsigned int>::digits) +
williamr@2:           (Bits <= std::numeric_limits<unsigned short>::digits) +
williamr@2:           (Bits <= std::numeric_limits<unsigned char>::digits)
williamr@2:         >::least  least;
williamr@2:       typedef typename int_fast_t<least>::fast  fast;
williamr@2:       // int_fast_t<> works correctly for unsigned too, in spite of the name.
williamr@2:   };
williamr@2: 
williamr@2:   //  integer templates specifying extreme value  ----------------------------//
williamr@2: 
williamr@2:   //  signed
williamr@2:   template< long MaxValue >   // maximum value to require support
williamr@2:   struct int_max_value_t 
williamr@2:   {
williamr@2:       typedef typename int_least_helper
williamr@2:         <
williamr@2:           (MaxValue <= integer_traits<long>::const_max) +
williamr@2:           (MaxValue <= integer_traits<int>::const_max) +
williamr@2:           (MaxValue <= integer_traits<short>::const_max) +
williamr@2:           (MaxValue <= integer_traits<signed char>::const_max)
williamr@2:         >::least  least;
williamr@2:       typedef typename int_fast_t<least>::fast  fast;
williamr@2:   };
williamr@2: 
williamr@2:   template< long MinValue >   // minimum value to require support
williamr@2:   struct int_min_value_t 
williamr@2:   {
williamr@2:       typedef typename int_least_helper
williamr@2:         <
williamr@2:           (MinValue >= integer_traits<long>::const_min) +
williamr@2:           (MinValue >= integer_traits<int>::const_min) +
williamr@2:           (MinValue >= integer_traits<short>::const_min) +
williamr@2:           (MinValue >= integer_traits<signed char>::const_min)
williamr@2:         >::least  least;
williamr@2:       typedef typename int_fast_t<least>::fast  fast;
williamr@2:   };
williamr@2: 
williamr@2:   //  unsigned
williamr@2:   template< unsigned long Value >   // maximum value to require support
williamr@2:   struct uint_value_t 
williamr@2:   {
williamr@2:       typedef typename int_least_helper
williamr@2:         < 
williamr@2:           5 +
williamr@2:           (Value <= integer_traits<unsigned long>::const_max) +
williamr@2:           (Value <= integer_traits<unsigned int>::const_max) +
williamr@2:           (Value <= integer_traits<unsigned short>::const_max) +
williamr@2:           (Value <= integer_traits<unsigned char>::const_max)
williamr@2:         >::least  least;
williamr@2:       typedef typename int_fast_t<least>::fast  fast;
williamr@2:   };
williamr@2: 
williamr@2: 
williamr@2: } // namespace boost
williamr@2: 
williamr@2: #endif  // BOOST_INTEGER_HPP