2 // Copyright 2005-2009 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 #if !defined(BOOST_FUNCTIONAL_HASH_HASH_HPP)
11 #define BOOST_FUNCTIONAL_HASH_HASH_HPP
13 #include <boost/functional/hash/hash_fwd.hpp>
15 #include <boost/functional/hash/detail/hash_float.hpp>
17 #include <boost/limits.hpp>
18 #include <boost/type_traits/is_enum.hpp>
19 #include <boost/type_traits/is_integral.hpp>
20 #include <boost/utility/enable_if.hpp>
22 #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
23 #include <boost/type_traits/is_pointer.hpp>
26 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
30 #if BOOST_WORKAROUND(__GNUC__, < 3) \
31 && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
32 #define BOOST_HASH_CHAR_TRAITS string_char_traits
34 #define BOOST_HASH_CHAR_TRAITS char_traits
41 struct enable_hash_value { typedef std::size_t type; };
43 template <typename T> struct basic_numbers {};
44 template <typename T> struct long_numbers;
45 template <typename T> struct ulong_numbers;
46 template <typename T> struct float_numbers {};
48 template <> struct basic_numbers<bool> :
49 boost::hash_detail::enable_hash_value {};
50 template <> struct basic_numbers<char> :
51 boost::hash_detail::enable_hash_value {};
52 template <> struct basic_numbers<unsigned char> :
53 boost::hash_detail::enable_hash_value {};
54 template <> struct basic_numbers<signed char> :
55 boost::hash_detail::enable_hash_value {};
56 template <> struct basic_numbers<short> :
57 boost::hash_detail::enable_hash_value {};
58 template <> struct basic_numbers<unsigned short> :
59 boost::hash_detail::enable_hash_value {};
60 template <> struct basic_numbers<int> :
61 boost::hash_detail::enable_hash_value {};
62 template <> struct basic_numbers<unsigned int> :
63 boost::hash_detail::enable_hash_value {};
64 template <> struct basic_numbers<long> :
65 boost::hash_detail::enable_hash_value {};
66 template <> struct basic_numbers<unsigned long> :
67 boost::hash_detail::enable_hash_value {};
69 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
70 template <> struct basic_numbers<wchar_t> :
71 boost::hash_detail::enable_hash_value {};
74 // long_numbers is defined like this to allow for separate
75 // specialization for long_long and int128_type, in case
77 template <typename T> struct long_numbers2 {};
78 template <typename T> struct ulong_numbers2 {};
79 template <typename T> struct long_numbers : long_numbers2<T> {};
80 template <typename T> struct ulong_numbers : ulong_numbers2<T> {};
82 #if !defined(BOOST_NO_LONG_LONG)
83 template <> struct long_numbers<boost::long_long_type> :
84 boost::hash_detail::enable_hash_value {};
85 template <> struct ulong_numbers<boost::ulong_long_type> :
86 boost::hash_detail::enable_hash_value {};
89 #if defined(BOOST_HAS_INT128)
90 template <> struct long_numbers2<boost::int128_type> :
91 boost::hash_detail::enable_hash_value {};
92 template <> struct ulong_numbers2<boost::uint128_type> :
93 boost::hash_detail::enable_hash_value {};
96 template <> struct float_numbers<float> :
97 boost::hash_detail::enable_hash_value {};
98 template <> struct float_numbers<double> :
99 boost::hash_detail::enable_hash_value {};
100 template <> struct float_numbers<long double> :
101 boost::hash_detail::enable_hash_value {};
104 template <typename T>
105 typename boost::hash_detail::basic_numbers<T>::type hash_value(T);
106 template <typename T>
107 typename boost::hash_detail::long_numbers<T>::type hash_value(T);
108 template <typename T>
109 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T);
111 template <typename T>
112 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
115 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
116 template <class T> std::size_t hash_value(T* const&);
118 template <class T> std::size_t hash_value(T*);
121 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
122 template< class T, unsigned N >
123 std::size_t hash_value(const T (&x)[N]);
125 template< class T, unsigned N >
126 std::size_t hash_value(T (&x)[N]);
129 template <class Ch, class A>
130 std::size_t hash_value(
131 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&);
133 template <typename T>
134 typename boost::hash_detail::float_numbers<T>::type hash_value(T);
136 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
137 std::size_t hash_value(std::type_index);
142 namespace hash_detail
145 inline std::size_t hash_value_signed(T val)
147 const int size_t_bits = std::numeric_limits<std::size_t>::digits;
148 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
149 const int length = (std::numeric_limits<T>::digits - 1)
152 std::size_t seed = 0;
153 T positive = val < 0 ? -1 - val : val;
155 // Hopefully, this loop can be unrolled.
156 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
158 seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2);
160 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
166 inline std::size_t hash_value_unsigned(T val)
168 const int size_t_bits = std::numeric_limits<std::size_t>::digits;
169 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
170 const int length = (std::numeric_limits<T>::digits - 1)
173 std::size_t seed = 0;
175 // Hopefully, this loop can be unrolled.
176 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
178 seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2);
180 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
186 template <typename T>
187 typename boost::hash_detail::basic_numbers<T>::type hash_value(T v)
189 return static_cast<std::size_t>(v);
192 template <typename T>
193 typename boost::hash_detail::long_numbers<T>::type hash_value(T v)
195 return hash_detail::hash_value_signed(v);
198 template <typename T>
199 typename boost::hash_detail::ulong_numbers<T>::type hash_value(T v)
201 return hash_detail::hash_value_unsigned(v);
204 template <typename T>
205 typename boost::enable_if<boost::is_enum<T>, std::size_t>::type
208 return static_cast<std::size_t>(v);
211 // Implementation by Alberto Barbati and Dave Harris.
212 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
213 template <class T> std::size_t hash_value(T* const& v)
215 template <class T> std::size_t hash_value(T* v)
218 #if defined(__VMS) && __INITIAL_POINTER_SIZE == 64
219 // for some reason ptrdiff_t on OpenVMS compiler with
220 // 64 bit is not 64 bit !!!
221 std::size_t x = static_cast<std::size_t>(
222 reinterpret_cast<long long int>(v));
224 std::size_t x = static_cast<std::size_t>(
225 reinterpret_cast<std::ptrdiff_t>(v));
230 #if defined(BOOST_MSVC)
231 #pragma warning(push)
232 #if BOOST_MSVC <= 1400
233 #pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to
234 // 'unsigned int', possible loss of data
235 // A misguided attempt to detect 64-bit
240 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
242 inline void hash_combine(std::size_t& seed, T& v)
245 inline void hash_combine(std::size_t& seed, T const& v)
248 boost::hash<T> hasher;
249 seed ^= hasher(v) + 0x9e3779b9 + (seed<<6) + (seed>>2);
252 #if defined(BOOST_MSVC)
257 inline std::size_t hash_range(It first, It last)
259 std::size_t seed = 0;
261 for(; first != last; ++first)
263 hash_combine(seed, *first);
270 inline void hash_range(std::size_t& seed, It first, It last)
272 for(; first != last; ++first)
274 hash_combine(seed, *first);
278 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
280 inline std::size_t hash_range(T* first, T* last)
282 std::size_t seed = 0;
284 for(; first != last; ++first)
286 boost::hash<T> hasher;
287 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
294 inline void hash_range(std::size_t& seed, T* first, T* last)
296 for(; first != last; ++first)
298 boost::hash<T> hasher;
299 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
304 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
305 template< class T, unsigned N >
306 inline std::size_t hash_value(const T (&x)[N])
308 return hash_range(x, x + N);
311 template< class T, unsigned N >
312 inline std::size_t hash_value(T (&x)[N])
314 return hash_range(x, x + N);
318 template <class Ch, class A>
319 inline std::size_t hash_value(
320 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v)
322 return hash_range(v.begin(), v.end());
325 template <typename T>
326 typename boost::hash_detail::float_numbers<T>::type hash_value(T v)
328 return boost::hash_detail::float_hash_value(v);
331 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
332 inline std::size_t hash_value(std::type_index v)
334 return v.hash_code();
342 // Define the specializations required by the standard. The general purpose
343 // boost::hash is defined later in extensions.hpp if
344 // BOOST_HASH_NO_EXTENSIONS is not defined.
346 // BOOST_HASH_SPECIALIZE - define a specialization for a type which is
349 // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is
352 // These are undefined later.
354 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
355 #define BOOST_HASH_SPECIALIZE(type) \
356 template <> struct hash<type> \
357 : public std::unary_function<type, std::size_t> \
359 std::size_t operator()(type v) const \
361 return boost::hash_value(v); \
365 #define BOOST_HASH_SPECIALIZE_REF(type) \
366 template <> struct hash<type> \
367 : public std::unary_function<type, std::size_t> \
369 std::size_t operator()(type const& v) const \
371 return boost::hash_value(v); \
375 #define BOOST_HASH_SPECIALIZE(type) \
376 template <> struct hash<type> \
377 : public std::unary_function<type, std::size_t> \
379 std::size_t operator()(type v) const \
381 return boost::hash_value(v); \
385 template <> struct hash<const type> \
386 : public std::unary_function<const type, std::size_t> \
388 std::size_t operator()(const type v) const \
390 return boost::hash_value(v); \
394 #define BOOST_HASH_SPECIALIZE_REF(type) \
395 template <> struct hash<type> \
396 : public std::unary_function<type, std::size_t> \
398 std::size_t operator()(type const& v) const \
400 return boost::hash_value(v); \
404 template <> struct hash<const type> \
405 : public std::unary_function<const type, std::size_t> \
407 std::size_t operator()(type const& v) const \
409 return boost::hash_value(v); \
414 BOOST_HASH_SPECIALIZE(bool)
415 BOOST_HASH_SPECIALIZE(char)
416 BOOST_HASH_SPECIALIZE(signed char)
417 BOOST_HASH_SPECIALIZE(unsigned char)
418 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
419 BOOST_HASH_SPECIALIZE(wchar_t)
421 BOOST_HASH_SPECIALIZE(short)
422 BOOST_HASH_SPECIALIZE(unsigned short)
423 BOOST_HASH_SPECIALIZE(int)
424 BOOST_HASH_SPECIALIZE(unsigned int)
425 BOOST_HASH_SPECIALIZE(long)
426 BOOST_HASH_SPECIALIZE(unsigned long)
428 BOOST_HASH_SPECIALIZE(float)
429 BOOST_HASH_SPECIALIZE(double)
430 BOOST_HASH_SPECIALIZE(long double)
432 BOOST_HASH_SPECIALIZE_REF(std::string)
433 #if !defined(BOOST_NO_STD_WSTRING)
434 BOOST_HASH_SPECIALIZE_REF(std::wstring)
437 #if !defined(BOOST_NO_LONG_LONG)
438 BOOST_HASH_SPECIALIZE(boost::long_long_type)
439 BOOST_HASH_SPECIALIZE(boost::ulong_long_type)
442 #if defined(BOOST_HAS_INT128)
443 BOOST_HASH_SPECIALIZE(boost::int128_type)
444 BOOST_HASH_SPECIALIZE(boost::uint128_type)
447 #if !defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
448 BOOST_HASH_SPECIALIZE(std::type_index)
451 #undef BOOST_HASH_SPECIALIZE
452 #undef BOOST_HASH_SPECIALIZE_REF
454 // Specializing boost::hash for pointers.
456 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
460 : public std::unary_function<T*, std::size_t>
462 std::size_t operator()(T* v) const
464 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590)
465 return boost::hash_value(v);
467 std::size_t x = static_cast<std::size_t>(
468 reinterpret_cast<std::ptrdiff_t>(v));
477 // For compilers without partial specialization, we define a
478 // boost::hash for all remaining types. But hash_impl is only defined
479 // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS
480 // is defined there will still be a compile error for types not supported
483 namespace hash_detail
485 template <bool IsPointer>
489 struct hash_impl<true>
493 : public std::unary_function<T, std::size_t>
495 std::size_t operator()(T val) const
497 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590)
498 return boost::hash_value(val);
500 std::size_t x = static_cast<std::size_t>(
501 reinterpret_cast<std::ptrdiff_t>(val));
510 template <class T> struct hash
511 : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value>
512 ::BOOST_NESTED_TEMPLATE inner<T>
519 #undef BOOST_HASH_CHAR_TRAITS
521 #endif // BOOST_FUNCTIONAL_HASH_HASH_HPP
523 // Include this outside of the include guards in case the file is included
524 // twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it
527 #if !defined(BOOST_HASH_NO_EXTENSIONS) \
528 && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP)
529 #include <boost/functional/hash/extensions.hpp>