1// Boost integer/integer_mask.hpp header file ------------------------------//
2
3// (C) Copyright Daryle Walker 2001.
4// Distributed under the Boost Software License, Version 1.0. (See
5// accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7
8// See http://www.boost.org for updates, documentation, and revision history.
9
10#ifndef BOOST_INTEGER_INTEGER_MASK_HPP
11#define BOOST_INTEGER_INTEGER_MASK_HPP
12
13#include <boost/integer_fwd.hpp> // self include
14
15#include <boost/config.hpp> // for BOOST_STATIC_CONSTANT
16#include <boost/integer.hpp> // for boost::uint_t
17
18#include <climits> // for UCHAR_MAX, etc.
19#include <cstddef> // for std::size_t
20
21#include <boost/limits.hpp> // for std::numeric_limits
22
23//
24// We simply cannot include this header on gcc without getting copious warnings of the kind:
25//
26// boost/integer/integer_mask.hpp:93:35: warning: use of C99 long long integer constant
27//
28// And yet there is no other reasonable implementation, so we declare this a system header
29// to suppress these warnings.
30//
31#if defined(__GNUC__) && (__GNUC__ >= 4)
32#pragma GCC system_header
33#endif
34
35namespace boost
36{
37
38
39// Specified single-bit mask class declaration -----------------------------//
40// (Lowest bit starts counting at 0.)
41
42template < std::size_t Bit >
43struct high_bit_mask_t
44{
45 typedef typename uint_t<(Bit + 1)>::least least;
46 typedef typename uint_t<(Bit + 1)>::fast fast;
47
48 BOOST_STATIC_CONSTANT( least, high_bit = (least( 1u ) << Bit) );
49 BOOST_STATIC_CONSTANT( fast, high_bit_fast = (fast( 1u ) << Bit) );
50
51 BOOST_STATIC_CONSTANT( std::size_t, bit_position = Bit );
52
53}; // boost::high_bit_mask_t
54
55
56// Specified bit-block mask class declaration ------------------------------//
57// Makes masks for the lowest N bits
58// (Specializations are needed when N fills up a type.)
59
60template < std::size_t Bits >
61struct low_bits_mask_t
62{
63 typedef typename uint_t<Bits>::least least;
64 typedef typename uint_t<Bits>::fast fast;
65
66 BOOST_STATIC_CONSTANT( least, sig_bits = (~( ~(least( 0u )) << Bits )) );
67 BOOST_STATIC_CONSTANT( fast, sig_bits_fast = fast(sig_bits) );
68
69 BOOST_STATIC_CONSTANT( std::size_t, bit_count = Bits );
70
71}; // boost::low_bits_mask_t
72
73
74#define BOOST_LOW_BITS_MASK_SPECIALIZE( Type ) \
75 template < > struct low_bits_mask_t< std::numeric_limits<Type>::digits > { \
76 typedef std::numeric_limits<Type> limits_type; \
77 typedef uint_t<limits_type::digits>::least least; \
78 typedef uint_t<limits_type::digits>::fast fast; \
79 BOOST_STATIC_CONSTANT( least, sig_bits = (~( least(0u) )) ); \
80 BOOST_STATIC_CONSTANT( fast, sig_bits_fast = fast(sig_bits) ); \
81 BOOST_STATIC_CONSTANT( std::size_t, bit_count = limits_type::digits ); \
82 }
83
84#ifdef BOOST_MSVC
85#pragma warning(push)
86#pragma warning(disable:4245) // 'initializing' : conversion from 'int' to 'const boost::low_bits_mask_t<8>::least', signed/unsigned mismatch
87#endif
88
89BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned char );
90
91#if USHRT_MAX > UCHAR_MAX
92BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned short );
93#endif
94
95#if UINT_MAX > USHRT_MAX
96BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned int );
97#endif
98
99#if ULONG_MAX > UINT_MAX
100BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned long );
101#endif
102
103#if defined(BOOST_HAS_LONG_LONG)
104 #if ((defined(ULLONG_MAX) && (ULLONG_MAX > ULONG_MAX)) ||\
105 (defined(ULONG_LONG_MAX) && (ULONG_LONG_MAX > ULONG_MAX)) ||\
106 (defined(ULONGLONG_MAX) && (ULONGLONG_MAX > ULONG_MAX)) ||\
107 (defined(_ULLONG_MAX) && (_ULLONG_MAX > ULONG_MAX)))
108 BOOST_LOW_BITS_MASK_SPECIALIZE( boost::ulong_long_type );
109 #endif
110#elif defined(BOOST_HAS_MS_INT64)
111 #if 18446744073709551615ui64 > ULONG_MAX
112 BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned __int64 );
113 #endif
114#endif
115
116#ifdef BOOST_MSVC
117#pragma warning(pop)
118#endif
119
120#undef BOOST_LOW_BITS_MASK_SPECIALIZE
121
122
123} // namespace boost
124
125
126#endif // BOOST_INTEGER_INTEGER_MASK_HPP
127