boost/container_hash/hash.hpp
// Copyright 2005-2014 Daniel James.
// Copyright 2021, 2022 Peter Dimov.
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
// Based on Peter Dimov's proposal
// http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf
// issue 6.18.
#ifndef BOOST_FUNCTIONAL_HASH_HASH_HPP
#define BOOST_FUNCTIONAL_HASH_HASH_HPP
#include <boost/container_hash/hash_fwd.hpp>
#include <boost/container_hash/is_range.hpp>
#include <boost/container_hash/is_contiguous_range.hpp>
#include <boost/container_hash/is_unordered_range.hpp>
#include <boost/container_hash/is_described_class.hpp>
#include <boost/container_hash/detail/hash_tuple.hpp>
#include <boost/container_hash/detail/hash_mix.hpp>
#include <boost/container_hash/detail/hash_range.hpp>
#include <boost/type_traits/is_enum.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/is_floating_point.hpp>
#include <boost/type_traits/is_signed.hpp>
#include <boost/type_traits/is_unsigned.hpp>
#include <boost/type_traits/make_unsigned.hpp>
#include <boost/type_traits/enable_if.hpp>
#include <boost/type_traits/conjunction.hpp>
#include <boost/type_traits/is_union.hpp>
#include <boost/describe/bases.hpp>
#include <boost/describe/members.hpp>
#include <boost/cstdint.hpp>
#if defined(BOOST_DESCRIBE_CXX14)
# include <boost/mp11/algorithm.hpp>
#endif
#include <string>
#include <iterator>
#include <complex>
#include <utility>
#include <limits>
#include <climits>
#include <cstring>
#if !defined(BOOST_NO_CXX11_SMART_PTR)
# include <memory>
#endif
#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
#include <typeindex>
#endif
#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
#include <system_error>
#endif
#if !defined(BOOST_NO_CXX17_HDR_OPTIONAL)
#include <optional>
#endif
#if !defined(BOOST_NO_CXX17_HDR_VARIANT)
#include <variant>
#endif
#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
# include <string_view>
#endif
namespace boost
{
//
// boost::hash_value
//
// integral types
namespace hash_detail
{
template<class T,
bool bigger_than_size_t = (sizeof(T) > sizeof(std::size_t)),
bool is_unsigned = boost::is_unsigned<T>::value,
std::size_t size_t_bits = sizeof(std::size_t) * CHAR_BIT,
std::size_t type_bits = sizeof(T) * CHAR_BIT>
struct hash_integral_impl;
template<class T, bool is_unsigned, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, false, is_unsigned, size_t_bits, type_bits>
{
static std::size_t fn( T v )
{
return static_cast<std::size_t>( v );
}
};
template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, true, false, size_t_bits, type_bits>
{
static std::size_t fn( T v )
{
typedef typename boost::make_unsigned<T>::type U;
if( v >= 0 )
{
return hash_integral_impl<U>::fn( static_cast<U>( v ) );
}
else
{
return ~hash_integral_impl<U>::fn( static_cast<U>( ~static_cast<U>( v ) ) );
}
}
};
template<class T> struct hash_integral_impl<T, true, true, 32, 64>
{
static std::size_t fn( T v )
{
std::size_t seed = 0;
seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
return seed;
}
};
template<class T> struct hash_integral_impl<T, true, true, 32, 128>
{
static std::size_t fn( T v )
{
std::size_t seed = 0;
seed = static_cast<std::size_t>( v >> 96 ) + hash_detail::hash_mix( seed );
seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
return seed;
}
};
template<class T> struct hash_integral_impl<T, true, true, 64, 128>
{
static std::size_t fn( T v )
{
std::size_t seed = 0;
seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
return seed;
}
};
} // namespace hash_detail
template <typename T>
typename boost::enable_if_<boost::is_integral<T>::value, std::size_t>::type
hash_value( T v )
{
return hash_detail::hash_integral_impl<T>::fn( v );
}
// enumeration types
template <typename T>
typename boost::enable_if_<boost::is_enum<T>::value, std::size_t>::type
hash_value( T v )
{
// This should in principle return the equivalent of
//
// boost::hash_value( to_underlying(v) );
//
// However, the C++03 implementation of underlying_type,
//
// conditional<is_signed<T>, make_signed<T>, make_unsigned<T>>::type::type
//
// generates a legitimate -Wconversion warning in is_signed,
// because -1 is not a valid enum value when all the enumerators
// are nonnegative.
//
// So the legacy implementation will have to do for now.
return static_cast<std::size_t>( v );
}
// floating point types
namespace hash_detail
{
template<class T,
std::size_t Bits = sizeof(T) * CHAR_BIT,
int Digits = std::numeric_limits<T>::digits>
struct hash_float_impl;
// float
template<class T, int Digits> struct hash_float_impl<T, 32, Digits>
{
static std::size_t fn( T v )
{
boost::uint32_t w;
std::memcpy( &w, &v, sizeof( v ) );
return w;
}
};
// double
template<class T, int Digits> struct hash_float_impl<T, 64, Digits>
{
static std::size_t fn( T v )
{
boost::uint64_t w;
std::memcpy( &w, &v, sizeof( v ) );
return hash_value( w );
}
};
// 80 bit long double in 12 bytes
template<class T> struct hash_float_impl<T, 96, 64>
{
static std::size_t fn( T v )
{
boost::uint64_t w[ 2 ] = {};
std::memcpy( &w, &v, 80 / CHAR_BIT );
std::size_t seed = 0;
seed = hash_value( w[0] ) + hash_detail::hash_mix( seed );
seed = hash_value( w[1] ) + hash_detail::hash_mix( seed );
return seed;
}
};
// 80 bit long double in 16 bytes
template<class T> struct hash_float_impl<T, 128, 64>
{
static std::size_t fn( T v )
{
boost::uint64_t w[ 2 ] = {};
std::memcpy( &w, &v, 80 / CHAR_BIT );
std::size_t seed = 0;
seed = hash_value( w[0] ) + hash_detail::hash_mix( seed );
seed = hash_value( w[1] ) + hash_detail::hash_mix( seed );
return seed;
}
};
// 128 bit long double
template<class T, int Digits> struct hash_float_impl<T, 128, Digits>
{
static std::size_t fn( T v )
{
boost::uint64_t w[ 2 ];
std::memcpy( &w, &v, sizeof( v ) );
std::size_t seed = 0;
#if defined(__FLOAT_WORD_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__
seed = hash_value( w[1] ) + hash_detail::hash_mix( seed );
seed = hash_value( w[0] ) + hash_detail::hash_mix( seed );
#else
seed = hash_value( w[0] ) + hash_detail::hash_mix( seed );
seed = hash_value( w[1] ) + hash_detail::hash_mix( seed );
#endif
return seed;
}
};
} // namespace hash_detail
template <typename T>
typename boost::enable_if_<boost::is_floating_point<T>::value, std::size_t>::type
hash_value( T v )
{
return boost::hash_detail::hash_float_impl<T>::fn( v + 0 );
}
// pointer types
// `x + (x >> 3)` adjustment by Alberto Barbati and Dave Harris.
template <class T> std::size_t hash_value( T* const& v )
{
boost::uintptr_t x = reinterpret_cast<boost::uintptr_t>( v );
return boost::hash_value( x + (x >> 3) );
}
// array types
template<class T, std::size_t N>
inline std::size_t hash_value( T const (&x)[ N ] )
{
return boost::hash_range( x, x + N );
}
template<class T, std::size_t N>
inline std::size_t hash_value( T (&x)[ N ] )
{
return boost::hash_range( x, x + N );
}
// complex
template <class T>
std::size_t hash_value( std::complex<T> const& v )
{
std::size_t re = boost::hash<T>()( v.real() );
std::size_t im = boost::hash<T>()( v.imag() );
return re + hash_detail::hash_mix( im );
}
// pair
template <class A, class B>
std::size_t hash_value( std::pair<A, B> const& v )
{
std::size_t seed = 0;
boost::hash_combine( seed, v.first );
boost::hash_combine( seed, v.second );
return seed;
}
// ranges (list, set, deque...)
template <typename T>
typename boost::enable_if_<container_hash::is_range<T>::value && !container_hash::is_contiguous_range<T>::value && !container_hash::is_unordered_range<T>::value, std::size_t>::type
hash_value( T const& v )
{
return boost::hash_range( v.begin(), v.end() );
}
// contiguous ranges (string, vector, array)
template <typename T>
typename boost::enable_if_<container_hash::is_contiguous_range<T>::value, std::size_t>::type
hash_value( T const& v )
{
return boost::hash_range( v.data(), v.data() + v.size() );
}
// unordered ranges (unordered_set, unordered_map)
template <typename T>
typename boost::enable_if_<container_hash::is_unordered_range<T>::value, std::size_t>::type
hash_value( T const& v )
{
return boost::hash_unordered_range( v.begin(), v.end() );
}
#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && ( \
( defined(_MSVC_STL_VERSION) && _MSVC_STL_VERSION < 142 ) || \
( !defined(_MSVC_STL_VERSION) && defined(_CPPLIB_VER) && _CPPLIB_VER >= 520 ) )
// resolve ambiguity with unconstrained stdext::hash_value in <xhash> :-/
template<template<class...> class L, class... T>
typename boost::enable_if_<container_hash::is_range<L<T...>>::value && !container_hash::is_contiguous_range<L<T...>>::value && !container_hash::is_unordered_range<L<T...>>::value, std::size_t>::type
hash_value( L<T...> const& v )
{
return boost::hash_range( v.begin(), v.end() );
}
// contiguous ranges (string, vector, array)
template<template<class...> class L, class... T>
typename boost::enable_if_<container_hash::is_contiguous_range<L<T...>>::value, std::size_t>::type
hash_value( L<T...> const& v )
{
return boost::hash_range( v.data(), v.data() + v.size() );
}
template<template<class, std::size_t> class L, class T, std::size_t N>
typename boost::enable_if_<container_hash::is_contiguous_range<L<T, N>>::value, std::size_t>::type
hash_value( L<T, N> const& v )
{
return boost::hash_range( v.data(), v.data() + v.size() );
}
// unordered ranges (unordered_set, unordered_map)
template<template<class...> class L, class... T>
typename boost::enable_if_<container_hash::is_unordered_range<L<T...>>::value, std::size_t>::type
hash_value( L<T...> const& v )
{
return boost::hash_unordered_range( v.begin(), v.end() );
}
#endif
// described classes
#if defined(BOOST_DESCRIBE_CXX14)
#if defined(_MSC_VER) && _MSC_VER == 1900
# pragma warning(push)
# pragma warning(disable: 4100) // unreferenced formal parameter
#endif
template <typename T>
typename boost::enable_if_<container_hash::is_described_class<T>::value, std::size_t>::type
hash_value( T const& v )
{
static_assert( !boost::is_union<T>::value, "described unions are not supported" );
std::size_t r = 0;
using Bd = describe::describe_bases<T, describe::mod_any_access>;
mp11::mp_for_each<Bd>([&](auto D){
using B = typename decltype(D)::type;
boost::hash_combine( r, (B const&)v );
});
using Md = describe::describe_members<T, describe::mod_any_access>;
mp11::mp_for_each<Md>([&](auto D){
boost::hash_combine( r, v.*D.pointer );
});
return r;
}
#if defined(_MSC_VER) && _MSC_VER == 1900
# pragma warning(pop)
#endif
#endif
// std::unique_ptr, std::shared_ptr
#if !defined(BOOST_NO_CXX11_SMART_PTR)
template <typename T>
std::size_t hash_value( std::shared_ptr<T> const& x )
{
return boost::hash_value( x.get() );
}
template <typename T, typename Deleter>
std::size_t hash_value( std::unique_ptr<T, Deleter> const& x )
{
return boost::hash_value( x.get() );
}
#endif
// std::type_index
#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
inline std::size_t hash_value( std::type_index const& v )
{
return v.hash_code();
}
#endif
// std::error_code, std::error_condition
#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
inline std::size_t hash_value( std::error_code const& v )
{
std::size_t seed = 0;
boost::hash_combine( seed, v.value() );
boost::hash_combine( seed, &v.category() );
return seed;
}
inline std::size_t hash_value( std::error_condition const& v )
{
std::size_t seed = 0;
boost::hash_combine( seed, v.value() );
boost::hash_combine( seed, &v.category() );
return seed;
}
#endif
// std::optional
#if !defined(BOOST_NO_CXX17_HDR_OPTIONAL)
template <typename T>
std::size_t hash_value( std::optional<T> const& v )
{
if( !v )
{
// Arbitray value for empty optional.
return 0x12345678;
}
else
{
return boost::hash<T>()(*v);
}
}
#endif
// std::variant
#if !defined(BOOST_NO_CXX17_HDR_VARIANT)
inline std::size_t hash_value( std::monostate )
{
return 0x87654321;
}
template <typename... Types>
std::size_t hash_value( std::variant<Types...> const& v )
{
std::size_t seed = 0;
hash_combine( seed, v.index() );
std::visit( [&seed](auto&& x) { hash_combine(seed, x); }, v );
return seed;
}
#endif
//
// boost::hash_combine
//
template <class T>
inline void hash_combine( std::size_t& seed, T const& v )
{
seed = boost::hash_detail::hash_mix( seed + 0x9e3779b9 + boost::hash<T>()( v ) );
}
//
// boost::hash_range
//
template <class It>
inline void hash_range( std::size_t& seed, It first, It last )
{
seed = hash_detail::hash_range( seed, first, last );
}
template <class It>
inline std::size_t hash_range( It first, It last )
{
std::size_t seed = 0;
hash_range( seed, first, last );
return seed;
}
//
// boost::hash_unordered_range
//
template <class It>
inline void hash_unordered_range( std::size_t& seed, It first, It last )
{
std::size_t r = 0;
std::size_t const s2( seed );
for( ; first != last; ++first )
{
std::size_t s3( s2 );
hash_combine<typename std::iterator_traits<It>::value_type>( s3, *first );
r += s3;
}
seed += r;
}
template <class It>
inline std::size_t hash_unordered_range( It first, It last )
{
std::size_t seed = 0;
hash_unordered_range( seed, first, last );
return seed;
}
//
// boost::hash
//
template <class T> struct hash
{
typedef T argument_type;
typedef std::size_t result_type;
std::size_t operator()( T const& val ) const
{
return hash_value( val );
}
};
#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && ( \
( defined(_MSVC_STL_VERSION) && _MSVC_STL_VERSION < 142 ) || \
( !defined(_MSVC_STL_VERSION) && defined(_CPPLIB_VER) && _CPPLIB_VER >= 520 ) )
// Dinkumware has stdext::hash_value for basic_string in <xhash> :-/
template<class E, class T, class A> struct hash< std::basic_string<E, T, A> >
{
typedef std::basic_string<E, T, A> argument_type;
typedef std::size_t result_type;
std::size_t operator()( std::basic_string<E, T, A> const& val ) const
{
return boost::hash_value( val );
}
};
#endif
// boost::unordered::hash_is_avalanching
namespace unordered
{
template<class T> struct hash_is_avalanching;
template<class Ch> struct hash_is_avalanching< boost::hash< std::basic_string<Ch> > >: boost::is_integral<Ch> {};
// boost::is_integral<char8_t> is false, but should be true (https://github.com/boostorg/type_traits/issues/175)
#if defined(__cpp_char8_t) && __cpp_char8_t >= 201811L
template<> struct hash_is_avalanching< boost::hash< std::basic_string<char8_t> > >: boost::true_type {};
#endif
#if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
template<class Ch> struct hash_is_avalanching< boost::hash< std::basic_string_view<Ch> > >: boost::is_integral<Ch> {};
#if defined(__cpp_char8_t) && __cpp_char8_t >= 201811L
template<> struct hash_is_avalanching< boost::hash< std::basic_string_view<char8_t> > >: boost::true_type {};
#endif
#endif
} // namespace unordered
} // namespace boost
#endif // #ifndef BOOST_FUNCTIONAL_HASH_HASH_HPP