1 // boost integer.hpp header file -------------------------------------------//
3 // Copyright Beman Dawes 1999.
4 // See accompanying license for terms and conditions of use.
6 // See http://www.boost.org/libs/integer for documentation.
9 // 22 Sep 01 Added value-based integer templates. (Daryle Walker)
10 // 01 Apr 01 Modified to use new <boost/limits.hpp> header. (John Maddock)
11 // 30 Jul 00 Add typename syntax fix (Jens Maurer)
12 // 28 Aug 99 Initial version
14 #ifndef BOOST_INTEGER_HPP
15 #define BOOST_INTEGER_HPP
17 #include <boost/integer_fwd.hpp> // self include
19 #include <boost/integer_traits.hpp> // for boost::integer_traits
20 #include <boost/limits.hpp> // for std::numeric_limits
25 // Helper templates ------------------------------------------------------//
27 // fast integers from least integers
28 // int_fast_t<> works correctly for unsigned too, in spite of the name.
29 template< typename LeastInt >
30 struct int_fast_t { typedef LeastInt fast; }; // imps may specialize
32 // convert category to type
33 template< int Category > struct int_least_helper {}; // default is empty
35 // specializatons: 1=long, 2=int, 3=short, 4=signed char,
36 // 6=unsigned long, 7=unsigned int, 8=unsigned short, 9=unsigned long
37 // no specializations for 0 and 5: requests for a type > long are in error
38 template<> struct int_least_helper<1> { typedef long least; };
39 template<> struct int_least_helper<2> { typedef int least; };
40 template<> struct int_least_helper<3> { typedef short least; };
41 template<> struct int_least_helper<4> { typedef signed char least; };
42 template<> struct int_least_helper<6> { typedef unsigned long least; };
43 template<> struct int_least_helper<7> { typedef unsigned int least; };
44 template<> struct int_least_helper<8> { typedef unsigned short least; };
45 template<> struct int_least_helper<9> { typedef unsigned char least; };
47 // integer templates specifying number of bits ---------------------------//
50 template< int Bits > // bits (including sign) required
53 typedef typename int_least_helper
55 (Bits-1 <= std::numeric_limits<long>::digits) +
56 (Bits-1 <= std::numeric_limits<int>::digits) +
57 (Bits-1 <= std::numeric_limits<short>::digits) +
58 (Bits-1 <= std::numeric_limits<signed char>::digits)
60 typedef typename int_fast_t<least>::fast fast;
64 template< int Bits > // bits required
67 typedef typename int_least_helper
70 (Bits <= std::numeric_limits<unsigned long>::digits) +
71 (Bits <= std::numeric_limits<unsigned int>::digits) +
72 (Bits <= std::numeric_limits<unsigned short>::digits) +
73 (Bits <= std::numeric_limits<unsigned char>::digits)
75 typedef typename int_fast_t<least>::fast fast;
76 // int_fast_t<> works correctly for unsigned too, in spite of the name.
79 // integer templates specifying extreme value ----------------------------//
82 template< long MaxValue > // maximum value to require support
83 struct int_max_value_t
85 typedef typename int_least_helper
87 (MaxValue <= integer_traits<long>::const_max) +
88 (MaxValue <= integer_traits<int>::const_max) +
89 (MaxValue <= integer_traits<short>::const_max) +
90 (MaxValue <= integer_traits<signed char>::const_max)
92 typedef typename int_fast_t<least>::fast fast;
95 template< long MinValue > // minimum value to require support
96 struct int_min_value_t
98 typedef typename int_least_helper
100 (MinValue >= integer_traits<long>::const_min) +
101 (MinValue >= integer_traits<int>::const_min) +
102 (MinValue >= integer_traits<short>::const_min) +
103 (MinValue >= integer_traits<signed char>::const_min)
105 typedef typename int_fast_t<least>::fast fast;
109 template< unsigned long Value > // maximum value to require support
112 typedef typename int_least_helper
115 (Value <= integer_traits<unsigned long>::const_max) +
116 (Value <= integer_traits<unsigned int>::const_max) +
117 (Value <= integer_traits<unsigned short>::const_max) +
118 (Value <= integer_traits<unsigned char>::const_max)
120 typedef typename int_fast_t<least>::fast fast;
126 #endif // BOOST_INTEGER_HPP