2 // Copyright 2005-2014 Daniel James.
3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 // Based on Peter Dimov's proposal
7 // http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf
10 // This also contains public domain code from MurmurHash. From the
13 // MurmurHash3 was written by Austin Appleby, and is placed in the public
14 // domain. The author hereby disclaims copyright to this source code.
16 #if !defined(BOOST_FUNCTIONAL_HASH_HASH_HPP)
17 #define BOOST_FUNCTIONAL_HASH_HASH_HPP
19 #include <boost/functional/hash/hash_fwd.hpp>
21 #include <boost/functional/hash/detail/hash_float.hpp>
23 #include <boost/limits.hpp>
24 #include <boost/type_traits/is_enum.hpp>
25 #include <boost/type_traits/is_integral.hpp>
26 #include <boost/utility/enable_if.hpp>
27 #include <boost/cstdint.hpp>
29 #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
30 #include <boost/type_traits/is_pointer.hpp>
33 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
37 #if defined(BOOST_MSVC)
40 #if BOOST_MSVC >= 1400
41 #pragma warning(disable:6295) // Ill-defined for-loop : 'unsigned int' values
42 // are always of range '0' to '4294967295'.
43 // Loop executes infinitely.
48 #if BOOST_WORKAROUND(__GNUC__, < 3) \
49 && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
50 #define BOOST_HASH_CHAR_TRAITS string_char_traits
52 #define BOOST_HASH_CHAR_TRAITS char_traits
56 # define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) _rotl(x,r)
58 # define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) (x << r) | (x >> (32 - r))
65 struct enable_hash_value { typedef std::size_t type; };
67 template <typename T> struct basic_numbers {};
68 template <typename T> struct long_numbers;
69 template <typename T> struct ulong_numbers;
70 template <typename T> struct float_numbers {};
72 template <> struct basic_numbers<bool> :
73 boost::hash_detail::enable_hash_value {};
74 template <> struct basic_numbers<char> :
75 boost::hash_detail::enable_hash_value {};
76 template <> struct basic_numbers<unsigned char> :
77 boost::hash_detail::enable_hash_value {};
78 template <> struct basic_numbers<signed char> :
79 boost::hash_detail::enable_hash_value {};
80 template <> struct basic_numbers<short> :
81 boost::hash_detail::enable_hash_value {};
82 template <> struct basic_numbers<unsigned short> :
83 boost::hash_detail::enable_hash_value {};
84 template <> struct basic_numbers<int> :
85 boost::hash_detail::enable_hash_value {};
86 template <> struct basic_numbers<unsigned int> :
87 boost::hash_detail::enable_hash_value {};
88 template <> struct basic_numbers<long> :
89 boost::hash_detail::enable_hash_value {};
90 template <> struct basic_numbers<unsigned long> :
91 boost::hash_detail::enable_hash_value {};
93 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
94 template <> struct basic_numbers<wchar_t> :
95 boost::hash_detail::enable_hash_value {};
98 // long_numbers is defined like this to allow for separate
99 // specialization for long_long and int128_type, in case
101 template <typename T> struct long_numbers2 {};
102 template <typename T> struct ulong_numbers2 {};
103 template <typename T> struct long_numbers : long_numbers2<T> {};
104 template <typename T> struct ulong_numbers : ulong_numbers2<T> {};
106 #if !defined(BOOST_NO_LONG_LONG)
107 template <> struct long_numbers<boost::long_long_type> :
108 boost::hash_detail::enable_hash_value {};
109 template <> struct ulong_numbers<boost::ulong_long_type> :
110 boost::hash_detail::enable_hash_value {};
113 #if defined(BOOST_HAS_INT128)
114 template <> struct long_numbers2<boost::int128_type> :
115 boost::hash_detail::enable_hash_value {};
116 template <> struct ulong_numbers2<boost::uint128_type> :
117 boost::hash_detail::enable_hash_value {};
120 template <> struct float_numbers<float> :
121 boost::hash_detail::enable_hash_value {};
122 template <> struct float_numbers<double> :
123 boost::hash_detail::enable_hash_value {};
124 template <> struct float_numbers<long double> :
125 boost::hash_detail::enable_hash_value {};
128 template <typename T>
129 typename boost::hash_detail::basic_numbers<T>::type hash_value(T);
130 template <typename T>
131 typename boost::hash_detail::long_numbers<T>::type hash_value(T);
132 template <typename T>
133 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T);
135 template <typename T>
136 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
139 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
140 template <class T> std::size_t hash_value(T* const&);
142 template <class T> std::size_t hash_value(T*);
145 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
146 template< class T, unsigned N >
147 std::size_t hash_value(const T (&x)[N]);
149 template< class T, unsigned N >
150 std::size_t hash_value(T (&x)[N]);
153 template <class Ch, class A>
154 std::size_t hash_value(
155 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&);
157 template <typename T>
158 typename boost::hash_detail::float_numbers<T>::type hash_value(T);
160 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
161 std::size_t hash_value(std::type_index);
166 namespace hash_detail
169 inline std::size_t hash_value_signed(T val)
171 const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits;
172 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
173 const int length = (std::numeric_limits<T>::digits - 1)
174 / static_cast<int>(size_t_bits);
176 std::size_t seed = 0;
177 T positive = val < 0 ? -1 - val : val;
179 // Hopefully, this loop can be unrolled.
180 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
182 seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2);
184 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
190 inline std::size_t hash_value_unsigned(T val)
192 const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits;
193 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
194 const int length = (std::numeric_limits<T>::digits - 1)
195 / static_cast<int>(size_t_bits);
197 std::size_t seed = 0;
199 // Hopefully, this loop can be unrolled.
200 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
202 seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2);
204 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
209 template <typename SizeT>
210 inline void hash_combine_impl(SizeT& seed, SizeT value)
212 seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2);
215 inline void hash_combine_impl(boost::uint32_t& h1,
218 const uint32_t c1 = 0xcc9e2d51;
219 const uint32_t c2 = 0x1b873593;
222 k1 = BOOST_FUNCTIONAL_HASH_ROTL32(k1,15);
226 h1 = BOOST_FUNCTIONAL_HASH_ROTL32(h1,13);
227 h1 = h1*5+0xe6546b64;
231 // Don't define 64-bit hash combine on platforms without 64 bit integers,
232 // and also not for 32-bit gcc as it warns about the 64-bit constant.
233 #if !defined(BOOST_NO_INT64_T) && \
234 !(defined(__GNUC__) && ULONG_MAX == 0xffffffff)
236 inline void hash_combine_impl(boost::uint64_t& h,
239 const boost::uint64_t m = UINT64_C(0xc6a4a7935bd1e995);
249 // Completely arbitrary number, to prevent 0's
250 // from hashing to 0.
254 #endif // BOOST_NO_INT64_T
257 template <typename T>
258 typename boost::hash_detail::basic_numbers<T>::type hash_value(T v)
260 return static_cast<std::size_t>(v);
263 template <typename T>
264 typename boost::hash_detail::long_numbers<T>::type hash_value(T v)
266 return hash_detail::hash_value_signed(v);
269 template <typename T>
270 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T v)
272 return hash_detail::hash_value_unsigned(v);
275 template <typename T>
276 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
279 return static_cast<std::size_t>(v);
282 // Implementation by Alberto Barbati and Dave Harris.
283 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
284 template <class T> std::size_t hash_value(T* const& v)
286 template <class T> std::size_t hash_value(T* v)
289 #if defined(__VMS) && __INITIAL_POINTER_SIZE == 64
290 // for some reason ptrdiff_t on OpenVMS compiler with
291 // 64 bit is not 64 bit !!!
292 std::size_t x = static_cast<std::size_t>(
293 reinterpret_cast<long long int>(v));
295 std::size_t x = static_cast<std::size_t>(
296 reinterpret_cast<std::ptrdiff_t>(v));
301 #if defined(BOOST_MSVC)
302 #pragma warning(push)
303 #if BOOST_MSVC <= 1400
304 #pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to
305 // 'unsigned int', possible loss of data
306 // A misguided attempt to detect 64-bit
312 inline void hash_combine(std::size_t& seed, T const& v)
314 boost::hash<T> hasher;
315 return boost::hash_detail::hash_combine_impl(seed, hasher(v));
318 #if defined(BOOST_MSVC)
323 inline std::size_t hash_range(It first, It last)
325 std::size_t seed = 0;
327 for(; first != last; ++first)
329 hash_combine(seed, *first);
336 inline void hash_range(std::size_t& seed, It first, It last)
338 for(; first != last; ++first)
340 hash_combine(seed, *first);
344 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
346 inline std::size_t hash_range(T* first, T* last)
348 std::size_t seed = 0;
350 for(; first != last; ++first)
352 boost::hash<T> hasher;
353 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
360 inline void hash_range(std::size_t& seed, T* first, T* last)
362 for(; first != last; ++first)
364 boost::hash<T> hasher;
365 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
370 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
371 template< class T, unsigned N >
372 inline std::size_t hash_value(const T (&x)[N])
374 return hash_range(x, x + N);
377 template< class T, unsigned N >
378 inline std::size_t hash_value(T (&x)[N])
380 return hash_range(x, x + N);
384 template <class Ch, class A>
385 inline std::size_t hash_value(
386 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v)
388 return hash_range(v.begin(), v.end());
391 template <typename T>
392 typename boost::hash_detail::float_numbers<T>::type hash_value(T v)
394 return boost::hash_detail::float_hash_value(v);
397 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
398 inline std::size_t hash_value(std::type_index v)
400 return v.hash_code();
408 // Define the specializations required by the standard. The general purpose
409 // boost::hash is defined later in extensions.hpp if
410 // BOOST_HASH_NO_EXTENSIONS is not defined.
412 // BOOST_HASH_SPECIALIZE - define a specialization for a type which is
415 // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is
416 // passed by const reference.
418 // These are undefined later.
420 #define BOOST_HASH_SPECIALIZE(type) \
421 template <> struct hash<type> \
422 : public std::unary_function<type, std::size_t> \
424 std::size_t operator()(type v) const \
426 return boost::hash_value(v); \
430 #define BOOST_HASH_SPECIALIZE_REF(type) \
431 template <> struct hash<type> \
432 : public std::unary_function<type, std::size_t> \
434 std::size_t operator()(type const& v) const \
436 return boost::hash_value(v); \
440 BOOST_HASH_SPECIALIZE(bool)
441 BOOST_HASH_SPECIALIZE(char)
442 BOOST_HASH_SPECIALIZE(signed char)
443 BOOST_HASH_SPECIALIZE(unsigned char)
444 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
445 BOOST_HASH_SPECIALIZE(wchar_t)
447 BOOST_HASH_SPECIALIZE(short)
448 BOOST_HASH_SPECIALIZE(unsigned short)
449 BOOST_HASH_SPECIALIZE(int)
450 BOOST_HASH_SPECIALIZE(unsigned int)
451 BOOST_HASH_SPECIALIZE(long)
452 BOOST_HASH_SPECIALIZE(unsigned long)
454 BOOST_HASH_SPECIALIZE(float)
455 BOOST_HASH_SPECIALIZE(double)
456 BOOST_HASH_SPECIALIZE(long double)
458 BOOST_HASH_SPECIALIZE_REF(std::string)
459 #if !defined(BOOST_NO_STD_WSTRING)
460 BOOST_HASH_SPECIALIZE_REF(std::wstring)
463 #if !defined(BOOST_NO_LONG_LONG)
464 BOOST_HASH_SPECIALIZE(boost::long_long_type)
465 BOOST_HASH_SPECIALIZE(boost::ulong_long_type)
468 #if defined(BOOST_HAS_INT128)
469 BOOST_HASH_SPECIALIZE(boost::int128_type)
470 BOOST_HASH_SPECIALIZE(boost::uint128_type)
473 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
474 BOOST_HASH_SPECIALIZE(std::type_index)
477 #undef BOOST_HASH_SPECIALIZE
478 #undef BOOST_HASH_SPECIALIZE_REF
480 // Specializing boost::hash for pointers.
482 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
486 : public std::unary_function<T*, std::size_t>
488 std::size_t operator()(T* v) const
490 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590)
491 return boost::hash_value(v);
493 std::size_t x = static_cast<std::size_t>(
494 reinterpret_cast<std::ptrdiff_t>(v));
503 // For compilers without partial specialization, we define a
504 // boost::hash for all remaining types. But hash_impl is only defined
505 // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS
506 // is defined there will still be a compile error for types not supported
509 namespace hash_detail
511 template <bool IsPointer>
515 struct hash_impl<true>
519 : public std::unary_function<T, std::size_t>
521 std::size_t operator()(T val) const
523 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590)
524 return boost::hash_value(val);
526 std::size_t x = static_cast<std::size_t>(
527 reinterpret_cast<std::ptrdiff_t>(val));
536 template <class T> struct hash
537 : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value>
538 ::BOOST_NESTED_TEMPLATE inner<T>
545 #undef BOOST_HASH_CHAR_TRAITS
546 #undef BOOST_FUNCTIONAL_HASH_ROTL32
548 #if defined(BOOST_MSVC)
552 #endif // BOOST_FUNCTIONAL_HASH_HASH_HPP
554 // Include this outside of the include guards in case the file is included
555 // twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it
558 #if !defined(BOOST_HASH_NO_EXTENSIONS) \
559 && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP)
560 #include <boost/functional/hash/extensions.hpp>