sl@0: //  Boost integer/integer_mask.hpp header file  ------------------------------//
sl@0: 
sl@0: //  (C) Copyright Daryle Walker 2001.
sl@0: //  Distributed under the Boost Software License, Version 1.0. (See
sl@0: //  accompanying file LICENSE_1_0.txt or copy at
sl@0: //  http://www.boost.org/LICENSE_1_0.txt)
sl@0: 
sl@0: //  See http://www.boost.org for updates, documentation, and revision history. 
sl@0: 
sl@0: #ifndef BOOST_INTEGER_INTEGER_MASK_HPP
sl@0: #define BOOST_INTEGER_INTEGER_MASK_HPP
sl@0: 
sl@0: #include <boost/integer_fwd.hpp>  // self include
sl@0: 
sl@0: #include <boost/config.hpp>   // for BOOST_STATIC_CONSTANT
sl@0: #include <boost/integer.hpp>  // for boost::uint_t
sl@0: 
sl@0: #include <climits>  // for UCHAR_MAX, etc.
sl@0: #include <cstddef>  // for std::size_t
sl@0: 
sl@0: #include <boost/limits.hpp>  // for std::numeric_limits
sl@0: 
sl@0: 
sl@0: namespace boost
sl@0: {
sl@0: 
sl@0: 
sl@0: //  Specified single-bit mask class declaration  -----------------------------//
sl@0: //  (Lowest bit starts counting at 0.)
sl@0: 
sl@0: template < std::size_t Bit >
sl@0: struct high_bit_mask_t
sl@0: {
sl@0:     typedef typename uint_t<(Bit + 1)>::least  least;
sl@0:     typedef typename uint_t<(Bit + 1)>::fast   fast;
sl@0: 
sl@0:     BOOST_STATIC_CONSTANT( least, high_bit = (least( 1u ) << Bit) );
sl@0:     BOOST_STATIC_CONSTANT( fast, high_bit_fast = (fast( 1u ) << Bit) );
sl@0: 
sl@0:     BOOST_STATIC_CONSTANT( std::size_t, bit_position = Bit );
sl@0: 
sl@0: };  // boost::high_bit_mask_t
sl@0: 
sl@0: 
sl@0: //  Specified bit-block mask class declaration  ------------------------------//
sl@0: //  Makes masks for the lowest N bits
sl@0: //  (Specializations are needed when N fills up a type.)
sl@0: 
sl@0: template < std::size_t Bits >
sl@0: struct low_bits_mask_t
sl@0: {
sl@0:     typedef typename uint_t<Bits>::least  least;
sl@0:     typedef typename uint_t<Bits>::fast   fast;
sl@0: 
sl@0:     BOOST_STATIC_CONSTANT( least, sig_bits = (~( ~(least( 0u )) << Bits )) );
sl@0:     BOOST_STATIC_CONSTANT( fast, sig_bits_fast = fast(sig_bits) );
sl@0: 
sl@0:     BOOST_STATIC_CONSTANT( std::size_t, bit_count = Bits );
sl@0: 
sl@0: };  // boost::low_bits_mask_t
sl@0: 
sl@0: 
sl@0: #define BOOST_LOW_BITS_MASK_SPECIALIZE( Type )                                  \
sl@0:   template <  >  struct low_bits_mask_t< std::numeric_limits<Type>::digits >  { \
sl@0:       typedef std::numeric_limits<Type>           limits_type;                  \
sl@0:       typedef uint_t<limits_type::digits>::least  least;                        \
sl@0:       typedef uint_t<limits_type::digits>::fast   fast;                         \
sl@0:       BOOST_STATIC_CONSTANT( least, sig_bits = (~( least(0u) )) );              \
sl@0:       BOOST_STATIC_CONSTANT( fast, sig_bits_fast = fast(sig_bits) );            \
sl@0:       BOOST_STATIC_CONSTANT( std::size_t, bit_count = limits_type::digits );    \
sl@0:   }
sl@0: 
sl@0: BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned char );
sl@0: 
sl@0: #if USHRT_MAX > UCHAR_MAX
sl@0: BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned short );
sl@0: #endif
sl@0: 
sl@0: #if UINT_MAX > USHRT_MAX
sl@0: BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned int );
sl@0: #endif
sl@0: 
sl@0: #if ULONG_MAX > UINT_MAX
sl@0: BOOST_LOW_BITS_MASK_SPECIALIZE( unsigned long );
sl@0: #endif
sl@0: 
sl@0: #undef BOOST_LOW_BITS_MASK_SPECIALIZE
sl@0: 
sl@0: 
sl@0: }  // namespace boost
sl@0: 
sl@0: 
sl@0: #endif  // BOOST_INTEGER_INTEGER_MASK_HPP