1
0
mirror of https://github.com/HarbourMasters/Shipwright.git synced 2024-12-26 01:58:51 -05:00
Shipwright/soh/include/boost_custom/container_hash/hash_32.hpp

173 lines
4.9 KiB
C++
Raw Normal View History

// 32 bit implementation based off of Boost hash
// Only implementing 32 bit versions integral and string based hashes
#ifndef BOOST_FUNCTIONAL_HASH_HASH_32_HPP
#define BOOST_FUNCTIONAL_HASH_HASH_32_HPP
#include <boost/container_hash/hash.hpp>
#include <boost_custom/container_hash/hash_fwd_32.hpp>
#include <boost_custom/container_hash/detail/hash_mix_32.hpp>
#include <boost_custom/container_hash/detail/hash_range_32.hpp>
#include <boost_custom/container_hash/version.hpp>
#if !BOOST_VERSION_HAS_HASH_RANGE
#include <boost/type_traits/is_unsigned.hpp>
#include <boost/type_traits/make_unsigned.hpp>
#if BOOST_WORKAROUND(__GNUC__, < 3) \
&& !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
#define BOOST_HASH_CHAR_TRAITS string_char_traits
#else
#define BOOST_HASH_CHAR_TRAITS char_traits
#endif
#endif // #if !BOOST_VERSION_HAS_HASH_RANGE
namespace boost
{
//
// boost::hash_value
//
// integral types
namespace hash_detail
{
template<class T,
bool bigger_than_size_t = (sizeof(T) > sizeof(uint32_t)),
bool is_unsigned = boost::is_unsigned<T>::value,
std::size_t size_t_bits = sizeof(uint32_t) * CHAR_BIT,
std::size_t type_bits = sizeof(T) * CHAR_BIT>
struct hash_integral_impl_32;
template<class T, bool is_unsigned, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl_32<T, false, is_unsigned, size_t_bits, type_bits>
{
static uint32_t fn( T v )
{
return static_cast<uint32_t>( v );
}
};
template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl_32<T, true, false, size_t_bits, type_bits>
{
static uint32_t fn( T v )
{
typedef typename boost::make_unsigned<T>::type U;
if( v >= 0 )
{
return hash_integral_impl_32<U>::fn( static_cast<U>( v ) );
}
else
{
return ~hash_integral_impl_32<U>::fn( static_cast<U>( ~static_cast<U>( v ) ) );
}
}
};
template<class T> struct hash_integral_impl_32<T, true, true, 32, 64>
{
static uint32_t fn( T v )
{
uint32_t seed = 0;
seed = static_cast<uint32_t>( v >> 32 ) + hash_detail::hash_mix_32( seed );
seed = static_cast<uint32_t>( v ) + hash_detail::hash_mix_32( seed );
return seed;
}
};
template<class T> struct hash_integral_impl_32<T, true, true, 32, 128>
{
static uint32_t fn( T v )
{
uint32_t seed = 0;
seed = static_cast<uint32_t>( v >> 96 ) + hash_detail::hash_mix_32( seed );
seed = static_cast<uint32_t>( v >> 64 ) + hash_detail::hash_mix_32( seed );
seed = static_cast<uint32_t>( v >> 32 ) + hash_detail::hash_mix_32( seed );
seed = static_cast<uint32_t>( v ) + hash_detail::hash_mix_32( seed );
return seed;
}
};
} // namespace hash_detail
template <typename T>
typename boost::enable_if_<boost::is_integral<T>::value, uint32_t>::type
hash_value_32( T v )
{
return hash_detail::hash_integral_impl_32<T>::fn( v );
}
// contiguous ranges (string, vector, array)
#if BOOST_VERSION_HAS_HASH_RANGE
template <typename T>
typename boost::enable_if_<container_hash::is_contiguous_range<T>::value, uint32_t>::type
hash_value_32( T const& v )
{
return boost::hash_range_32( v.data(), v.data() + v.size() );
}
#else
template <class Ch, class A>
inline uint32_t hash_value_32(
std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v)
{
return boost::hash_range_32( v.data(), v.data() + v.size() );
}
#endif
//
// boost::hash_combine
//
template <class T>
inline void hash_combine_32( uint32_t& seed, T const& v )
{
seed = boost::hash_detail::hash_mix_32( seed + 0x9e3779b9 + boost::hash_32<T>()( v ) );
}
//
// boost::hash_range
//
template <class It>
inline void hash_range_32( uint32_t& seed, It first, It last )
{
seed = hash_detail::hash_range_32( seed, first, last );
}
template <class It>
inline uint32_t hash_range_32( It first, It last )
{
uint32_t seed = 0;
hash_range_32( seed, first, last );
return seed;
}
//
// boost::hash
//
template <class T> struct hash_32
{
typedef T argument_type;
typedef uint32_t result_type;
uint32_t operator()( T const& val ) const
{
return hash_value_32( val );
}
};
} // namespace boost
#undef BOOST_HASH_CHAR_TRAITS
#endif // #ifndef BOOST_FUNCTIONAL_HASH_HASH_32_HPP