1
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)
5
6// Based on Peter Dimov's proposal
7// http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf
8// issue 6.18.
9//
10// This also contains public domain code from MurmurHash. From the
11// MurmurHash header:
12
13// MurmurHash3 was written by Austin Appleby, and is placed in the public
14// domain. The author hereby disclaims copyright to this source code.
15
16#if !defined(BOOST_FUNCTIONAL_HASH_HASH_HPP)
17#define BOOST_FUNCTIONAL_HASH_HASH_HPP
18
19#include <boost/container_hash/hash_fwd.hpp>
20#include <functional>
21#include <boost/container_hash/detail/hash_float.hpp>
22#include <string>
23#include <boost/limits.hpp>
24#include <boost/type_traits/is_enum.hpp>
25#include <boost/type_traits/is_integral.hpp>
26#include <boost/core/enable_if.hpp>
27#include <boost/cstdint.hpp>
28
29#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
30#include <boost/type_traits/is_pointer.hpp>
31#endif
32
33#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
34#include <typeindex>
35#endif
36
37#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
38#include <system_error>
39#endif
40
41#if defined(BOOST_MSVC)
42#pragma warning(push)
43
44#if BOOST_MSVC >= 1400
45#pragma warning(disable:6295) // Ill-defined for-loop : 'unsigned int' values
46 // are always of range '0' to '4294967295'.
47 // Loop executes infinitely.
48#endif
49
50#endif
51
52#if BOOST_WORKAROUND(__GNUC__, < 3) \
53 && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
54#define BOOST_HASH_CHAR_TRAITS string_char_traits
55#else
56#define BOOST_HASH_CHAR_TRAITS char_traits
57#endif
58
59#if defined(_MSC_VER)
60# define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) _rotl(x,r)
61#else
62# define BOOST_FUNCTIONAL_HASH_ROTL32(x, r) (x << r) | (x >> (32 - r))
63#endif
64
65// Detect whether standard library has C++17 headers
66
67#if !defined(BOOST_HASH_CXX17)
68# if defined(BOOST_MSVC)
69# if defined(_HAS_CXX17) && _HAS_CXX17
70# define BOOST_HASH_CXX17 1
71# endif
72# elif defined(__cplusplus) && __cplusplus >= 201703
73# define BOOST_HASH_CXX17 1
74# endif
75#endif
76
77#if !defined(BOOST_HASH_CXX17)
78# define BOOST_HASH_CXX17 0
79#endif
80
81#if BOOST_HASH_CXX17 && defined(__has_include)
82# if !defined(BOOST_HASH_HAS_STRING_VIEW) && __has_include(<string_view>)
83# define BOOST_HASH_HAS_STRING_VIEW 1
84# endif
85# if !defined(BOOST_HASH_HAS_OPTIONAL) && __has_include(<optional>)
86# define BOOST_HASH_HAS_OPTIONAL 1
87# endif
88# if !defined(BOOST_HASH_HAS_VARIANT) && __has_include(<variant>)
89# define BOOST_HASH_HAS_VARIANT 1
90# endif
91#endif
92
93#if !defined(BOOST_HASH_HAS_STRING_VIEW)
94# define BOOST_HASH_HAS_STRING_VIEW 0
95#endif
96
97#if !defined(BOOST_HASH_HAS_OPTIONAL)
98# define BOOST_HASH_HAS_OPTIONAL 0
99#endif
100
101#if !defined(BOOST_HASH_HAS_VARIANT)
102# define BOOST_HASH_HAS_VARIANT 0
103#endif
104
105#if BOOST_HASH_HAS_STRING_VIEW
106# include <string_view>
107#endif
108
109#if BOOST_HASH_HAS_OPTIONAL
110# include <optional>
111#endif
112
113#if BOOST_HASH_HAS_VARIANT
114# include <variant>
115#endif
116
117namespace boost
118{
119 namespace hash_detail
120 {
121#if defined(_HAS_AUTO_PTR_ETC) && !_HAS_AUTO_PTR_ETC
122 template <typename T>
123 struct hash_base
124 {
125 typedef T argument_type;
126 typedef std::size_t result_type;
127 };
128#else
129 template <typename T>
130 struct hash_base : std::unary_function<T, std::size_t> {};
131#endif
132
133 struct enable_hash_value { typedef std::size_t type; };
134
135 template <typename T> struct basic_numbers {};
136 template <typename T> struct long_numbers;
137 template <typename T> struct ulong_numbers;
138 template <typename T> struct float_numbers {};
139
140 template <> struct basic_numbers<bool> :
141 boost::hash_detail::enable_hash_value {};
142 template <> struct basic_numbers<char> :
143 boost::hash_detail::enable_hash_value {};
144 template <> struct basic_numbers<unsigned char> :
145 boost::hash_detail::enable_hash_value {};
146 template <> struct basic_numbers<signed char> :
147 boost::hash_detail::enable_hash_value {};
148 template <> struct basic_numbers<short> :
149 boost::hash_detail::enable_hash_value {};
150 template <> struct basic_numbers<unsigned short> :
151 boost::hash_detail::enable_hash_value {};
152 template <> struct basic_numbers<int> :
153 boost::hash_detail::enable_hash_value {};
154 template <> struct basic_numbers<unsigned int> :
155 boost::hash_detail::enable_hash_value {};
156 template <> struct basic_numbers<long> :
157 boost::hash_detail::enable_hash_value {};
158 template <> struct basic_numbers<unsigned long> :
159 boost::hash_detail::enable_hash_value {};
160
161#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
162 template <> struct basic_numbers<wchar_t> :
163 boost::hash_detail::enable_hash_value {};
164#endif
165
166#if !defined(BOOST_NO_CXX11_CHAR16_T)
167 template <> struct basic_numbers<char16_t> :
168 boost::hash_detail::enable_hash_value {};
169#endif
170
171#if !defined(BOOST_NO_CXX11_CHAR32_T)
172 template <> struct basic_numbers<char32_t> :
173 boost::hash_detail::enable_hash_value {};
174#endif
175
176 // long_numbers is defined like this to allow for separate
177 // specialization for long_long and int128_type, in case
178 // they conflict.
179 template <typename T> struct long_numbers2 {};
180 template <typename T> struct ulong_numbers2 {};
181 template <typename T> struct long_numbers : long_numbers2<T> {};
182 template <typename T> struct ulong_numbers : ulong_numbers2<T> {};
183
184#if !defined(BOOST_NO_LONG_LONG)
185 template <> struct long_numbers<boost::long_long_type> :
186 boost::hash_detail::enable_hash_value {};
187 template <> struct ulong_numbers<boost::ulong_long_type> :
188 boost::hash_detail::enable_hash_value {};
189#endif
190
191#if defined(BOOST_HAS_INT128)
192 template <> struct long_numbers2<boost::int128_type> :
193 boost::hash_detail::enable_hash_value {};
194 template <> struct ulong_numbers2<boost::uint128_type> :
195 boost::hash_detail::enable_hash_value {};
196#endif
197
198 template <> struct float_numbers<float> :
199 boost::hash_detail::enable_hash_value {};
200 template <> struct float_numbers<double> :
201 boost::hash_detail::enable_hash_value {};
202 template <> struct float_numbers<long double> :
203 boost::hash_detail::enable_hash_value {};
204 }
205
206 template <typename T>
207 typename boost::hash_detail::basic_numbers<T>::type hash_value(T);
208 template <typename T>
209 typename boost::hash_detail::long_numbers<T>::type hash_value(T);
210 template <typename T>
211 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T);
212
213 template <typename T>
214 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
215 hash_value(T);
216
217#if !BOOST_WORKAROUND(__DMC__, <= 0x848)
218 template <class T> std::size_t hash_value(T* const&);
219#else
220 template <class T> std::size_t hash_value(T*);
221#endif
222
223#if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
224 template< class T, unsigned N >
225 std::size_t hash_value(const T (&x)[N]);
226
227 template< class T, unsigned N >
228 std::size_t hash_value(T (&x)[N]);
229#endif
230
231 template <class Ch, class A>
232 std::size_t hash_value(
233 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&);
234
235#if BOOST_HASH_HAS_STRING_VIEW
236 template <class Ch>
237 std::size_t hash_value(
238 std::basic_string_view<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch> > const&);
239#endif
240
241 template <typename T>
242 typename boost::hash_detail::float_numbers<T>::type hash_value(T);
243
244#if BOOST_HASH_HAS_OPTIONAL
245 template <typename T>
246 std::size_t hash_value(std::optional<T> const&);
247#endif
248
249#if BOOST_HASH_HAS_VARIANT
250 std::size_t hash_value(std::monostate);
251 template <typename... Types>
252 std::size_t hash_value(std::variant<Types...> const&);
253#endif
254
255#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
256 std::size_t hash_value(std::type_index);
257#endif
258
259#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
260 std::size_t hash_value(std::error_code const&);
261 std::size_t hash_value(std::error_condition const&);
262#endif
263
264 // Implementation
265
266 namespace hash_detail
267 {
268 template <class T>
269 inline std::size_t hash_value_signed(T val)
270 {
271 const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits;
272 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
273 const int length = (std::numeric_limits<T>::digits - 1)
274 / static_cast<int>(size_t_bits);
275
276 std::size_t seed = 0;
277 T positive = val < 0 ? -1 - val : val;
278
279 // Hopefully, this loop can be unrolled.
280 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
281 {
282 seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2);
283 }
284 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
285
286 return seed;
287 }
288
289 template <class T>
290 inline std::size_t hash_value_unsigned(T val)
291 {
292 const unsigned int size_t_bits = std::numeric_limits<std::size_t>::digits;
293 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
294 const int length = (std::numeric_limits<T>::digits - 1)
295 / static_cast<int>(size_t_bits);
296
297 std::size_t seed = 0;
298
299 // Hopefully, this loop can be unrolled.
300 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
301 {
302 seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2);
303 }
304 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
305
306 return seed;
307 }
308
309 template <typename SizeT>
310 inline void hash_combine_impl(SizeT& seed, SizeT value)
311 {
312 seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2);
313 }
314
315 inline void hash_combine_impl(boost::uint32_t& h1,
316 boost::uint32_t k1)
317 {
318 const uint32_t c1 = 0xcc9e2d51;
319 const uint32_t c2 = 0x1b873593;
320
321 k1 *= c1;
322 k1 = BOOST_FUNCTIONAL_HASH_ROTL32(k1,15);
323 k1 *= c2;
324
325 h1 ^= k1;
326 h1 = BOOST_FUNCTIONAL_HASH_ROTL32(h1,13);
327 h1 = h1*5+0xe6546b64;
328 }
329
330
331// Don't define 64-bit hash combine on platforms without 64 bit integers,
332// and also not for 32-bit gcc as it warns about the 64-bit constant.
333#if !defined(BOOST_NO_INT64_T) && \
334 !(defined(__GNUC__) && ULONG_MAX == 0xffffffff)
335
336 inline void hash_combine_impl(boost::uint64_t& h,
337 boost::uint64_t k)
338 {
339 const boost::uint64_t m = UINT64_C(0xc6a4a7935bd1e995);
340 const int r = 47;
341
342 k *= m;
343 k ^= k >> r;
344 k *= m;
345
346 h ^= k;
347 h *= m;
348
349 // Completely arbitrary number, to prevent 0's
350 // from hashing to 0.
351 h += 0xe6546b64;
352 }
353
354#endif // BOOST_NO_INT64_T
355 }
356
357 template <typename T>
358 typename boost::hash_detail::basic_numbers<T>::type hash_value(T v)
359 {
360 return static_cast<std::size_t>(v);
361 }
362
363 template <typename T>
364 typename boost::hash_detail::long_numbers<T>::type hash_value(T v)
365 {
366 return hash_detail::hash_value_signed(v);
367 }
368
369 template <typename T>
370 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T v)
371 {
372 return hash_detail::hash_value_unsigned(v);
373 }
374
375 template <typename T>
376 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
377 hash_value(T v)
378 {
379 return static_cast<std::size_t>(v);
380 }
381
382 // Implementation by Alberto Barbati and Dave Harris.
383#if !BOOST_WORKAROUND(__DMC__, <= 0x848)
384 template <class T> std::size_t hash_value(T* const& v)
385#else
386 template <class T> std::size_t hash_value(T* v)
387#endif
388 {
389#if defined(__VMS) && __INITIAL_POINTER_SIZE == 64
390 // for some reason ptrdiff_t on OpenVMS compiler with
391 // 64 bit is not 64 bit !!!
392 std::size_t x = static_cast<std::size_t>(
393 reinterpret_cast<long long int>(v));
394#else
395 std::size_t x = static_cast<std::size_t>(
396 reinterpret_cast<std::ptrdiff_t>(v));
397#endif
398 return x + (x >> 3);
399 }
400
401#if defined(BOOST_MSVC)
402#pragma warning(push)
403#if BOOST_MSVC <= 1400
404#pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to
405 // 'unsigned int', possible loss of data
406 // A misguided attempt to detect 64-bit
407 // incompatability.
408#endif
409#endif
410
411 template <class T>
412 inline void hash_combine(std::size_t& seed, T const& v)
413 {
414 boost::hash<T> hasher;
415 return boost::hash_detail::hash_combine_impl(seed, hasher(v));
416 }
417
418#if defined(BOOST_MSVC)
419#pragma warning(pop)
420#endif
421
422 template <class It>
423 inline std::size_t hash_range(It first, It last)
424 {
425 std::size_t seed = 0;
426
427 for(; first != last; ++first)
428 {
429 hash_combine(seed, *first);
430 }
431
432 return seed;
433 }
434
435 template <class It>
436 inline void hash_range(std::size_t& seed, It first, It last)
437 {
438 for(; first != last; ++first)
439 {
440 hash_combine(seed, *first);
441 }
442 }
443
444#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
445 template <class T>
446 inline std::size_t hash_range(T* first, T* last)
447 {
448 std::size_t seed = 0;
449
450 for(; first != last; ++first)
451 {
452 boost::hash<T> hasher;
453 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
454 }
455
456 return seed;
457 }
458
459 template <class T>
460 inline void hash_range(std::size_t& seed, T* first, T* last)
461 {
462 for(; first != last; ++first)
463 {
464 boost::hash<T> hasher;
465 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
466 }
467 }
468#endif
469
470#if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
471 template< class T, unsigned N >
472 inline std::size_t hash_value(const T (&x)[N])
473 {
474 return hash_range(x, x + N);
475 }
476
477 template< class T, unsigned N >
478 inline std::size_t hash_value(T (&x)[N])
479 {
480 return hash_range(x, x + N);
481 }
482#endif
483
484 template <class Ch, class A>
485 inline std::size_t hash_value(
486 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v)
487 {
488 return hash_range(v.begin(), v.end());
489 }
490
491#if BOOST_HASH_HAS_STRING_VIEW
492 template <class Ch>
493 inline std::size_t hash_value(
494 std::basic_string_view<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch> > const& v)
495 {
496 return hash_range(v.begin(), v.end());
497 }
498#endif
499
500 template <typename T>
501 typename boost::hash_detail::float_numbers<T>::type hash_value(T v)
502 {
503 return boost::hash_detail::float_hash_value(v);
504 }
505
506#if BOOST_HASH_HAS_OPTIONAL
507 template <typename T>
508 inline std::size_t hash_value(std::optional<T> const& v) {
509 if (!v) {
510 // Arbitray value for empty optional.
511 return 0x12345678;
512 } else {
513 boost::hash<T> hf;
514 return hf(*v);
515 }
516 }
517#endif
518
519#if BOOST_HASH_HAS_VARIANT
520 inline std::size_t hash_value(std::monostate) {
521 return 0x87654321;
522 }
523
524 template <typename... Types>
525 inline std::size_t hash_value(std::variant<Types...> const& v) {
526 std::size_t seed = 0;
527 hash_combine(seed, v.index());
528 std::visit([&seed](auto&& x) { hash_combine(seed, x); }, v);
529 return seed;
530 }
531#endif
532
533
534#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
535 inline std::size_t hash_value(std::type_index v)
536 {
537 return v.hash_code();
538 }
539#endif
540
541#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
542 inline std::size_t hash_value(std::error_code const& v) {
543 std::size_t seed = 0;
544 hash_combine(seed, v.value());
545 hash_combine(seed, &v.category());
546 return seed;
547 }
548
549 inline std::size_t hash_value(std::error_condition const& v) {
550 std::size_t seed = 0;
551 hash_combine(seed, v.value());
552 hash_combine(seed, &v.category());
553 return seed;
554 }
555#endif
556
557 //
558 // boost::hash
559 //
560
561 // Define the specializations required by the standard. The general purpose
562 // boost::hash is defined later in extensions.hpp if
563 // BOOST_HASH_NO_EXTENSIONS is not defined.
564
565 // BOOST_HASH_SPECIALIZE - define a specialization for a type which is
566 // passed by copy.
567 //
568 // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is
569 // passed by const reference.
570 //
571 // These are undefined later.
572
573#define BOOST_HASH_SPECIALIZE(type) \
574 template <> struct hash<type> \
575 : public boost::hash_detail::hash_base<type> \
576 { \
577 std::size_t operator()(type v) const \
578 { \
579 return boost::hash_value(v); \
580 } \
581 };
582
583#define BOOST_HASH_SPECIALIZE_REF(type) \
584 template <> struct hash<type> \
585 : public boost::hash_detail::hash_base<type> \
586 { \
587 std::size_t operator()(type const& v) const \
588 { \
589 return boost::hash_value(v); \
590 } \
591 };
592
593#define BOOST_HASH_SPECIALIZE_TEMPLATE_REF(type) \
594 struct hash<type> \
595 : public boost::hash_detail::hash_base<type> \
596 { \
597 std::size_t operator()(type const& v) const \
598 { \
599 return boost::hash_value(v); \
600 } \
601 };
602
603 BOOST_HASH_SPECIALIZE(bool)
604 BOOST_HASH_SPECIALIZE(char)
605 BOOST_HASH_SPECIALIZE(signed char)
606 BOOST_HASH_SPECIALIZE(unsigned char)
607#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
608 BOOST_HASH_SPECIALIZE(wchar_t)
609#endif
610#if !defined(BOOST_NO_CXX11_CHAR16_T)
611 BOOST_HASH_SPECIALIZE(char16_t)
612#endif
613#if !defined(BOOST_NO_CXX11_CHAR32_T)
614 BOOST_HASH_SPECIALIZE(char32_t)
615#endif
616 BOOST_HASH_SPECIALIZE(short)
617 BOOST_HASH_SPECIALIZE(unsigned short)
618 BOOST_HASH_SPECIALIZE(int)
619 BOOST_HASH_SPECIALIZE(unsigned int)
620 BOOST_HASH_SPECIALIZE(long)
621 BOOST_HASH_SPECIALIZE(unsigned long)
622
623 BOOST_HASH_SPECIALIZE(float)
624 BOOST_HASH_SPECIALIZE(double)
625 BOOST_HASH_SPECIALIZE(long double)
626
627 BOOST_HASH_SPECIALIZE_REF(std::string)
628#if !defined(BOOST_NO_STD_WSTRING) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
629 BOOST_HASH_SPECIALIZE_REF(std::wstring)
630#endif
631#if !defined(BOOST_NO_CXX11_CHAR16_T)
632 BOOST_HASH_SPECIALIZE_REF(std::basic_string<char16_t>)
633#endif
634#if !defined(BOOST_NO_CXX11_CHAR32_T)
635 BOOST_HASH_SPECIALIZE_REF(std::basic_string<char32_t>)
636#endif
637
638#if BOOST_HASH_HAS_STRING_VIEW
639 BOOST_HASH_SPECIALIZE_REF(std::string_view)
640# if !defined(BOOST_NO_STD_WSTRING) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
641 BOOST_HASH_SPECIALIZE_REF(std::wstring_view)
642# endif
643# if !defined(BOOST_NO_CXX11_CHAR16_T)
644 BOOST_HASH_SPECIALIZE_REF(std::basic_string_view<char16_t>)
645# endif
646# if !defined(BOOST_NO_CXX11_CHAR32_T)
647 BOOST_HASH_SPECIALIZE_REF(std::basic_string_view<char32_t>)
648# endif
649#endif
650
651#if !defined(BOOST_NO_LONG_LONG)
652 BOOST_HASH_SPECIALIZE(boost::long_long_type)
653 BOOST_HASH_SPECIALIZE(boost::ulong_long_type)
654#endif
655
656#if defined(BOOST_HAS_INT128)
657 BOOST_HASH_SPECIALIZE(boost::int128_type)
658 BOOST_HASH_SPECIALIZE(boost::uint128_type)
659#endif
660
661#if BOOST_HASH_HAS_OPTIONAL
662 template <typename T>
663 BOOST_HASH_SPECIALIZE_TEMPLATE_REF(std::optional<T>)
664#endif
665
666#if !defined(BOOST_HASH_HAS_VARIANT)
667 template <typename... T>
668 BOOST_HASH_SPECIALIZE_TEMPLATE_REF(std::variant<T...>)
669 BOOST_HASH_SPECIALIZE(std::monostate)
670#endif
671
672#if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
673 BOOST_HASH_SPECIALIZE(std::type_index)
674#endif
675
676#undef BOOST_HASH_SPECIALIZE
677#undef BOOST_HASH_SPECIALIZE_REF
678#undef BOOST_HASH_SPECIALIZE_TEMPLATE_REF
679
680// Specializing boost::hash for pointers.
681
682#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
683
684 template <class T>
685 struct hash<T*>
686 : public boost::hash_detail::hash_base<T*>
687 {
688 std::size_t operator()(T* v) const
689 {
690#if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590)
691 return boost::hash_value(v);
692#else
693 std::size_t x = static_cast<std::size_t>(
694 reinterpret_cast<std::ptrdiff_t>(v));
695
696 return x + (x >> 3);
697#endif
698 }
699 };
700
701#else
702
703 // For compilers without partial specialization, we define a
704 // boost::hash for all remaining types. But hash_impl is only defined
705 // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS
706 // is defined there will still be a compile error for types not supported
707 // in the standard.
708
709 namespace hash_detail
710 {
711 template <bool IsPointer>
712 struct hash_impl;
713
714 template <>
715 struct hash_impl<true>
716 {
717 template <class T>
718 struct inner
719 : public boost::hash_detail::hash_base<T>
720 {
721 std::size_t operator()(T val) const
722 {
723#if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590)
724 return boost::hash_value(val);
725#else
726 std::size_t x = static_cast<std::size_t>(
727 reinterpret_cast<std::ptrdiff_t>(val));
728
729 return x + (x >> 3);
730#endif
731 }
732 };
733 };
734 }
735
736 template <class T> struct hash
737 : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value>
738 ::BOOST_NESTED_TEMPLATE inner<T>
739 {
740 };
741
742#endif
743}
744
745#undef BOOST_HASH_CHAR_TRAITS
746#undef BOOST_FUNCTIONAL_HASH_ROTL32
747
748#if defined(BOOST_MSVC)
749#pragma warning(pop)
750#endif
751
752#endif // BOOST_FUNCTIONAL_HASH_HASH_HPP
753
754// Include this outside of the include guards in case the file is included
755// twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it
756// undefined.
757
758#if !defined(BOOST_HASH_NO_EXTENSIONS) \
759 && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP)
760#include <boost/container_hash/extensions.hpp>
761#endif
762