1 // boost integer.hpp header file -------------------------------------------//
3 // (C) Copyright Beman Dawes 1999. Permission to copy, use, modify, sell
4 // and distribute this software is granted provided this copyright
5 // notice appears in all copies. This software is provided "as is" without
6 // express or implied warranty, and with no claim as to its suitability for
9 // See http://www.boost.org for most recent version including documentation.
12 // 22 Sep 01 Added value-based integer templates. (Daryle Walker)
13 // 01 Apr 01 Modified to use new <boost/limits.hpp> header. (John Maddock)
14 // 30 Jul 00 Add typename syntax fix (Jens Maurer)
15 // 28 Aug 99 Initial version
17 #ifndef BOOST_INTEGER_HPP
18 #define BOOST_INTEGER_HPP
20 #include <boost/integer_fwd.hpp> // self include
22 #include <boost/integer_traits.hpp> // for boost::integer_traits
23 #include <boost/limits.hpp> // for std::numeric_limits
28 // Helper templates ------------------------------------------------------//
30 // fast integers from least integers
31 // int_fast_t<> works correctly for unsigned too, in spite of the name.
32 template< typename LeastInt >
33 struct int_fast_t { typedef LeastInt fast; }; // imps may specialize
35 // convert category to type
36 template< int Category > struct int_least_helper {}; // default is empty
38 // specializatons: 1=long, 2=int, 3=short, 4=signed char,
39 // 6=unsigned long, 7=unsigned int, 8=unsigned short, 9=unsigned long
40 // no specializations for 0 and 5: requests for a type > long are in error
41 template<> struct int_least_helper<1> { typedef long least; };
42 template<> struct int_least_helper<2> { typedef int least; };
43 template<> struct int_least_helper<3> { typedef short least; };
44 template<> struct int_least_helper<4> { typedef signed char least; };
45 template<> struct int_least_helper<6> { typedef unsigned long least; };
46 template<> struct int_least_helper<7> { typedef unsigned int least; };
47 template<> struct int_least_helper<8> { typedef unsigned short least; };
48 template<> struct int_least_helper<9> { typedef unsigned char least; };
50 // integer templates specifying number of bits ---------------------------//
53 template< int Bits > // bits (including sign) required
56 typedef typename int_least_helper
58 (Bits-1 <= std::numeric_limits<long>::digits) +
59 (Bits-1 <= std::numeric_limits<int>::digits) +
60 (Bits-1 <= std::numeric_limits<short>::digits) +
61 (Bits-1 <= std::numeric_limits<signed char>::digits)
63 typedef typename int_fast_t<least>::fast fast;
67 template< int Bits > // bits required
70 typedef typename int_least_helper
73 (Bits <= std::numeric_limits<unsigned long>::digits) +
74 (Bits <= std::numeric_limits<unsigned int>::digits) +
75 (Bits <= std::numeric_limits<unsigned short>::digits) +
76 (Bits <= std::numeric_limits<unsigned char>::digits)
78 typedef typename int_fast_t<least>::fast fast;
79 // int_fast_t<> works correctly for unsigned too, in spite of the name.
82 // integer templates specifying extreme value ----------------------------//
85 template< long MaxValue > // maximum value to require support
86 struct int_max_value_t
88 typedef typename int_least_helper
90 (MaxValue <= integer_traits<long>::const_max) +
91 (MaxValue <= integer_traits<int>::const_max) +
92 (MaxValue <= integer_traits<short>::const_max) +
93 (MaxValue <= integer_traits<signed char>::const_max)
95 typedef typename int_fast_t<least>::fast fast;
98 template< long MinValue > // minimum value to require support
99 struct int_min_value_t
101 typedef typename int_least_helper
103 (MinValue >= integer_traits<long>::const_min) +
104 (MinValue >= integer_traits<int>::const_min) +
105 (MinValue >= integer_traits<short>::const_min) +
106 (MinValue >= integer_traits<signed char>::const_min)
108 typedef typename int_fast_t<least>::fast fast;
112 template< unsigned long Value > // maximum value to require support
115 typedef typename int_least_helper
118 (Value <= integer_traits<unsigned long>::const_max) +
119 (Value <= integer_traits<unsigned int>::const_max) +
120 (Value <= integer_traits<unsigned short>::const_max) +
121 (Value <= integer_traits<unsigned char>::const_max)
123 typedef typename int_fast_t<least>::fast fast;
129 #endif // BOOST_INTEGER_HPP