boost/functional/hash/hash.hpp
// Copyright 2005-2014 Daniel James. // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://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. // // This also contains public domain code from MurmurHash. From the // MurmurHash header: // MurmurHash3 was written by Austin Appleby, and is placed in the public // domain. The author hereby disclaims copyright to this source code. #if !defined(BOOST_FUNCTIONAL_HASH_HASH_HPP) #define BOOST_FUNCTIONAL_HASH_HASH_HPP #include <boost/functional/hash/hash_fwd.hpp> #include <functional> #include <boost/functional/hash/detail/hash_float.hpp> #include <string> #include <boost/limits.hpp> #include <boost/type_traits/is_enum.hpp> #include <boost/type_traits/is_integral.hpp> #include <boost/utility/enable_if.hpp> #include <boost/cstdint.hpp> #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) #include <boost/type_traits/is_pointer.hpp> #endif #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX) #include <typeindex> #endif #if defined(BOOST_MSVC) #pragma warning(push) #if BOOST_MSVC >= 1400 #pragma warning(disable:6295) // Ill-defined for-loop : 'unsigned int' values // are always of range '0' to '4294967295'. // Loop executes infinitely. #endif #endif #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 #if defined(_MSC_VER) # define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) _rotl(x,r) #else # define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) (x << r) | (x >> (32 - r)) #endif namespace boost { namespace hash_detail { struct enable_hash_value { typedef std::size_t type; }; template <typename T> struct basic_numbers {}; template <typename T> struct long_numbers; template <typename T> struct ulong_numbers; template <typename T> struct float_numbers {}; template <> struct basic_numbers<bool> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<char> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<unsigned char> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<signed char> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<short> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<unsigned short> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<int> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<unsigned int> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<long> : boost::hash_detail::enable_hash_value {}; template <> struct basic_numbers<unsigned long> : boost::hash_detail::enable_hash_value {}; #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) template <> struct basic_numbers<wchar_t> : boost::hash_detail::enable_hash_value {}; #endif // long_numbers is defined like this to allow for separate // specialization for long_long and int128_type, in case // they conflict. template <typename T> struct long_numbers2 {}; template <typename T> struct ulong_numbers2 {}; template <typename T> struct long_numbers : long_numbers2<T> {}; template <typename T> struct ulong_numbers : ulong_numbers2<T> {}; #if !defined(BOOST_NO_LONG_LONG) template <> struct long_numbers<boost::long_long_type> : boost::hash_detail::enable_hash_value {}; template <> struct ulong_numbers<boost::ulong_long_type> : boost::hash_detail::enable_hash_value {}; #endif #if defined(BOOST_HAS_INT128) template <> struct long_numbers2<boost::int128_type> : boost::hash_detail::enable_hash_value {}; template <> struct ulong_numbers2<boost::uint128_type> : boost::hash_detail::enable_hash_value {}; #endif template <> struct float_numbers<float> : boost::hash_detail::enable_hash_value {}; template <> struct float_numbers<double> : boost::hash_detail::enable_hash_value {}; template <> struct float_numbers<long double> : boost::hash_detail::enable_hash_value {}; } template <typename T> typename boost::hash_detail::basic_numbers<T>::type hash_value(T); template <typename T> typename boost::hash_detail::long_numbers<T>::type hash_value(T); template <typename T> typename boost::hash_detail::ulong_numbers<T>::type hash_value(T); template <typename T> typename boost::enable_if<boost::is_enum<T>, std::size_t>::type hash_value(T); #if !BOOST_WORKAROUND(__DMC__, <= 0x848) template <class T> std::size_t hash_value(T* const&); #else template <class T> std::size_t hash_value(T*); #endif #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) template< class T, unsigned N > std::size_t hash_value(const T (&x)[N]); template< class T, unsigned N > std::size_t hash_value(T (&x)[N]); #endif template <class Ch, class A> std::size_t hash_value( std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&); template <typename T> typename boost::hash_detail::float_numbers<T>::type hash_value(T); #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX) std::size_t hash_value(std::type_index); #endif // Implementation namespace hash_detail { template <class T> inline std::size_t hash_value_signed(T val) { const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits; // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1 const int length = (std::numeric_limits<T>::digits - 1) / static_cast<int>(size_t_bits); std::size_t seed = 0; T positive = val < 0 ? -1 - val : val; // Hopefully, this loop can be unrolled. for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits) { seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2); } seed ^= (std::size_t) val + (seed<<6) + (seed>>2); return seed; } template <class T> inline std::size_t hash_value_unsigned(T val) { const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits; // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1 const int length = (std::numeric_limits<T>::digits - 1) / static_cast<int>(size_t_bits); std::size_t seed = 0; // Hopefully, this loop can be unrolled. for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits) { seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2); } seed ^= (std::size_t) val + (seed<<6) + (seed>>2); return seed; } template <typename SizeT> inline void hash_combine_impl(SizeT& seed, SizeT value) { seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2); } inline void hash_combine_impl(boost::uint32_t& h1, boost::uint32_t k1) { const uint32_t c1 = 0xcc9e2d51; const uint32_t c2 = 0x1b873593; k1 *= c1; k1 = BOOST_FUNCTIONAL_HASH_ROTL32(k1,15); k1 *= c2; h1 ^= k1; h1 = BOOST_FUNCTIONAL_HASH_ROTL32(h1,13); h1 = h1*5+0xe6546b64; } // Don't define 64-bit hash combine on platforms without 64 bit integers, // and also not for 32-bit gcc as it warns about the 64-bit constant. #if !defined(BOOST_NO_INT64_T) && \ !(defined(__GNUC__) && ULONG_MAX == 0xffffffff) inline void hash_combine_impl(boost::uint64_t& h, boost::uint64_t k) { const boost::uint64_t m = UINT64_C(0xc6a4a7935bd1e995); const int r = 47; k *= m; k ^= k >> r; k *= m; h ^= k; h *= m; // Completely arbitrary number, to prevent 0's // from hashing to 0. h += 0xe6546b64; } #endif // BOOST_NO_INT64_T } template <typename T> typename boost::hash_detail::basic_numbers<T>::type hash_value(T v) { return static_cast<std::size_t>(v); } template <typename T> typename boost::hash_detail::long_numbers<T>::type hash_value(T v) { return hash_detail::hash_value_signed(v); } template <typename T> typename boost::hash_detail::ulong_numbers<T>::type hash_value(T v) { return hash_detail::hash_value_unsigned(v); } template <typename T> typename boost::enable_if<boost::is_enum<T>, std::size_t>::type hash_value(T v) { return static_cast<std::size_t>(v); } // Implementation by Alberto Barbati and Dave Harris. #if !BOOST_WORKAROUND(__DMC__, <= 0x848) template <class T> std::size_t hash_value(T* const& v) #else template <class T> std::size_t hash_value(T* v) #endif { #if defined(__VMS) && __INITIAL_POINTER_SIZE == 64 // for some reason ptrdiff_t on OpenVMS compiler with // 64 bit is not 64 bit !!! std::size_t x = static_cast<std::size_t>( reinterpret_cast<long long int>(v)); #else std::size_t x = static_cast<std::size_t>( reinterpret_cast<std::ptrdiff_t>(v)); #endif return x + (x >> 3); } #if defined(BOOST_MSVC) #pragma warning(push) #if BOOST_MSVC <= 1400 #pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to // 'unsigned int', possible loss of data // A misguided attempt to detect 64-bit // incompatability. #endif #endif template <class T> inline void hash_combine(std::size_t& seed, T const& v) { boost::hash<T> hasher; return boost::hash_detail::hash_combine_impl(seed, hasher(v)); } #if defined(BOOST_MSVC) #pragma warning(pop) #endif template <class It> inline std::size_t hash_range(It first, It last) { std::size_t seed = 0; for(; first != last; ++first) { hash_combine(seed, *first); } return seed; } template <class It> inline void hash_range(std::size_t& seed, It first, It last) { for(; first != last; ++first) { hash_combine(seed, *first); } } #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) template <class T> inline std::size_t hash_range(T* first, T* last) { std::size_t seed = 0; for(; first != last; ++first) { boost::hash<T> hasher; seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2); } return seed; } template <class T> inline void hash_range(std::size_t& seed, T* first, T* last) { for(; first != last; ++first) { boost::hash<T> hasher; seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2); } } #endif #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) template< class T, unsigned N > inline std::size_t hash_value(const T (&x)[N]) { return hash_range(x, x + N); } template< class T, unsigned N > inline std::size_t hash_value(T (&x)[N]) { return hash_range(x, x + N); } #endif template <class Ch, class A> inline std::size_t hash_value( std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v) { return hash_range(v.begin(), v.end()); } template <typename T> typename boost::hash_detail::float_numbers<T>::type hash_value(T v) { return boost::hash_detail::float_hash_value(v); } #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX) inline std::size_t hash_value(std::type_index v) { return v.hash_code(); } #endif // // boost::hash // // Define the specializations required by the standard. The general purpose // boost::hash is defined later in extensions.hpp if // BOOST_HASH_NO_EXTENSIONS is not defined. // BOOST_HASH_SPECIALIZE - define a specialization for a type which is // passed by copy. // // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is // passed by const reference. // // These are undefined later. #define BOOST_HASH_SPECIALIZE(type) \ template <> struct hash<type> \ : public std::unary_function<type, std::size_t> \ { \ std::size_t operator()(type v) const \ { \ return boost::hash_value(v); \ } \ }; #define BOOST_HASH_SPECIALIZE_REF(type) \ template <> struct hash<type> \ : public std::unary_function<type, std::size_t> \ { \ std::size_t operator()(type const& v) const \ { \ return boost::hash_value(v); \ } \ }; BOOST_HASH_SPECIALIZE(bool) BOOST_HASH_SPECIALIZE(char) BOOST_HASH_SPECIALIZE(signed char) BOOST_HASH_SPECIALIZE(unsigned char) #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) BOOST_HASH_SPECIALIZE(wchar_t) #endif BOOST_HASH_SPECIALIZE(short) BOOST_HASH_SPECIALIZE(unsigned short) BOOST_HASH_SPECIALIZE(int) BOOST_HASH_SPECIALIZE(unsigned int) BOOST_HASH_SPECIALIZE(long) BOOST_HASH_SPECIALIZE(unsigned long) BOOST_HASH_SPECIALIZE(float) BOOST_HASH_SPECIALIZE(double) BOOST_HASH_SPECIALIZE(long double) BOOST_HASH_SPECIALIZE_REF(std::string) #if !defined(BOOST_NO_STD_WSTRING) && !defined(BOOST_NO_INTRINSIC_WCHAR_T) BOOST_HASH_SPECIALIZE_REF(std::wstring) #endif #if !defined(BOOST_NO_LONG_LONG) BOOST_HASH_SPECIALIZE(boost::long_long_type) BOOST_HASH_SPECIALIZE(boost::ulong_long_type) #endif #if defined(BOOST_HAS_INT128) BOOST_HASH_SPECIALIZE(boost::int128_type) BOOST_HASH_SPECIALIZE(boost::uint128_type) #endif #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX) BOOST_HASH_SPECIALIZE(std::type_index) #endif #undef BOOST_HASH_SPECIALIZE #undef BOOST_HASH_SPECIALIZE_REF // Specializing boost::hash for pointers. #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) template <class T> struct hash<T*> : public std::unary_function<T*, std::size_t> { std::size_t operator()(T* v) const { #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) return boost::hash_value(v); #else std::size_t x = static_cast<std::size_t>( reinterpret_cast<std::ptrdiff_t>(v)); return x + (x >> 3); #endif } }; #else // For compilers without partial specialization, we define a // boost::hash for all remaining types. But hash_impl is only defined // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS // is defined there will still be a compile error for types not supported // in the standard. namespace hash_detail { template <bool IsPointer> struct hash_impl; template <> struct hash_impl<true> { template <class T> struct inner : public std::unary_function<T, std::size_t> { std::size_t operator()(T val) const { #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590) return boost::hash_value(val); #else std::size_t x = static_cast<std::size_t>( reinterpret_cast<std::ptrdiff_t>(val)); return x + (x >> 3); #endif } }; }; } template <class T> struct hash : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value> ::BOOST_NESTED_TEMPLATE inner<T> { }; #endif } #undef BOOST_HASH_CHAR_TRAITS #undef BOOST_FUNCTIONAL_HASH_ROTL32 #if defined(BOOST_MSVC) #pragma warning(pop) #endif #endif // BOOST_FUNCTIONAL_HASH_HASH_HPP // Include this outside of the include guards in case the file is included // twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it // undefined. #if !defined(BOOST_HASH_NO_EXTENSIONS) \ && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP) #include <boost/functional/hash/extensions.hpp> #endif