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>
19 #if defined(BOOST_HASH_NO_IMPLICIT_CASTS)
20 #include <boost/static_assert.hpp>
23 #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
24 #include <boost/type_traits/is_pointer.hpp>
27 #if BOOST_WORKAROUND(__GNUC__, < 3) \
28 && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
29 #define BOOST_HASH_CHAR_TRAITS string_char_traits
31 #define BOOST_HASH_CHAR_TRAITS char_traits
36 #if defined(BOOST_HASH_NO_IMPLICIT_CASTS)
38 // If you get a static assertion here, it's because hash_value
39 // isn't declared for your type.
41 std::size_t hash_value(T const&) {
42 BOOST_STATIC_ASSERT((T*) 0 && false);
48 std::size_t hash_value(bool);
49 std::size_t hash_value(char);
50 std::size_t hash_value(unsigned char);
51 std::size_t hash_value(signed char);
52 std::size_t hash_value(short);
53 std::size_t hash_value(unsigned short);
54 std::size_t hash_value(int);
55 std::size_t hash_value(unsigned int);
56 std::size_t hash_value(long);
57 std::size_t hash_value(unsigned long);
59 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
60 std::size_t hash_value(wchar_t);
63 #if !defined(BOOST_NO_LONG_LONG)
64 std::size_t hash_value(boost::long_long_type);
65 std::size_t hash_value(boost::ulong_long_type);
68 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
69 template <class T> std::size_t hash_value(T* const&);
71 template <class T> std::size_t hash_value(T*);
74 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
75 template< class T, unsigned N >
76 std::size_t hash_value(const T (&x)[N]);
78 template< class T, unsigned N >
79 std::size_t hash_value(T (&x)[N]);
82 std::size_t hash_value(float v);
83 std::size_t hash_value(double v);
84 std::size_t hash_value(long double v);
86 template <class Ch, class A>
87 std::size_t hash_value(
88 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&);
95 inline std::size_t hash_value_signed(T val)
97 const int size_t_bits = std::numeric_limits<std::size_t>::digits;
98 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
99 const int length = (std::numeric_limits<T>::digits - 1)
102 std::size_t seed = 0;
103 T positive = val < 0 ? -1 - val : val;
105 // Hopefully, this loop can be unrolled.
106 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
108 seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2);
110 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
116 inline std::size_t hash_value_unsigned(T val)
118 const int size_t_bits = std::numeric_limits<std::size_t>::digits;
119 // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1
120 const int length = (std::numeric_limits<T>::digits - 1)
123 std::size_t seed = 0;
125 // Hopefully, this loop can be unrolled.
126 for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits)
128 seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2);
130 seed ^= (std::size_t) val + (seed<<6) + (seed>>2);
136 inline std::size_t hash_value(bool v)
138 return static_cast<std::size_t>(v);
141 inline std::size_t hash_value(char v)
143 return static_cast<std::size_t>(v);
146 inline std::size_t hash_value(unsigned char v)
148 return static_cast<std::size_t>(v);
151 inline std::size_t hash_value(signed char v)
153 return static_cast<std::size_t>(v);
156 inline std::size_t hash_value(short v)
158 return static_cast<std::size_t>(v);
161 inline std::size_t hash_value(unsigned short v)
163 return static_cast<std::size_t>(v);
166 inline std::size_t hash_value(int v)
168 return static_cast<std::size_t>(v);
171 inline std::size_t hash_value(unsigned int v)
173 return static_cast<std::size_t>(v);
176 inline std::size_t hash_value(long v)
178 return static_cast<std::size_t>(v);
181 inline std::size_t hash_value(unsigned long v)
183 return static_cast<std::size_t>(v);
186 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
187 inline std::size_t hash_value(wchar_t v)
189 return static_cast<std::size_t>(v);
193 #if !defined(BOOST_NO_LONG_LONG)
194 inline std::size_t hash_value(boost::long_long_type v)
196 return hash_detail::hash_value_signed(v);
199 inline std::size_t hash_value(boost::ulong_long_type v)
201 return hash_detail::hash_value_unsigned(v);
205 // Implementation by Alberto Barbati and Dave Harris.
206 #if !BOOST_WORKAROUND(__DMC__, <= 0x848)
207 template <class T> std::size_t hash_value(T* const& v)
209 template <class T> std::size_t hash_value(T* v)
212 std::size_t x = static_cast<std::size_t>(
213 reinterpret_cast<std::ptrdiff_t>(v));
218 #if defined(BOOST_MSVC)
219 #pragma warning(push)
220 #if BOOST_MSVC <= 1400
221 #pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to
222 // 'unsigned int', possible loss of data
223 // A misguided attempt to detect 64-bit
228 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
230 inline void hash_combine(std::size_t& seed, T& v)
233 inline void hash_combine(std::size_t& seed, T const& v)
236 boost::hash<T> hasher;
237 seed ^= hasher(v) + 0x9e3779b9 + (seed<<6) + (seed>>2);
240 #if defined(BOOST_MSVC)
245 inline std::size_t hash_range(It first, It last)
247 std::size_t seed = 0;
249 for(; first != last; ++first)
251 hash_combine(seed, *first);
258 inline void hash_range(std::size_t& seed, It first, It last)
260 for(; first != last; ++first)
262 hash_combine(seed, *first);
266 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
268 inline std::size_t hash_range(T* first, T* last)
270 std::size_t seed = 0;
272 for(; first != last; ++first)
274 boost::hash<T> hasher;
275 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
282 inline void hash_range(std::size_t& seed, T* first, T* last)
284 for(; first != last; ++first)
286 boost::hash<T> hasher;
287 seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2);
292 #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
293 template< class T, unsigned N >
294 inline std::size_t hash_value(const T (&x)[N])
296 return hash_range(x, x + N);
299 template< class T, unsigned N >
300 inline std::size_t hash_value(T (&x)[N])
302 return hash_range(x, x + N);
306 template <class Ch, class A>
307 inline std::size_t hash_value(
308 std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v)
310 return hash_range(v.begin(), v.end());
313 inline std::size_t hash_value(float v)
315 return boost::hash_detail::float_hash_value(v);
318 inline std::size_t hash_value(double v)
320 return boost::hash_detail::float_hash_value(v);
323 inline std::size_t hash_value(long double v)
325 return boost::hash_detail::float_hash_value(v);
332 // Define the specializations required by the standard. The general purpose
333 // boost::hash is defined later in extensions.hpp if
334 // BOOST_HASH_NO_EXTENSIONS is not defined.
336 // BOOST_HASH_SPECIALIZE - define a specialization for a type which is
339 // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is
342 // These are undefined later.
344 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
345 #define BOOST_HASH_SPECIALIZE(type) \
346 template <> struct hash<type> \
347 : public std::unary_function<type, std::size_t> \
349 std::size_t operator()(type v) const \
351 return boost::hash_value(v); \
355 #define BOOST_HASH_SPECIALIZE_REF(type) \
356 template <> struct hash<type> \
357 : public std::unary_function<type, std::size_t> \
359 std::size_t operator()(type const& v) const \
361 return boost::hash_value(v); \
365 #define BOOST_HASH_SPECIALIZE(type) \
366 template <> struct hash<type> \
367 : public std::unary_function<type, std::size_t> \
369 std::size_t operator()(type v) const \
371 return boost::hash_value(v); \
375 template <> struct hash<const type> \
376 : public std::unary_function<const type, std::size_t> \
378 std::size_t operator()(const type v) const \
380 return boost::hash_value(v); \
384 #define BOOST_HASH_SPECIALIZE_REF(type) \
385 template <> struct hash<type> \
386 : public std::unary_function<type, std::size_t> \
388 std::size_t operator()(type const& v) const \
390 return boost::hash_value(v); \
394 template <> struct hash<const type> \
395 : public std::unary_function<const type, std::size_t> \
397 std::size_t operator()(type const& v) const \
399 return boost::hash_value(v); \
404 BOOST_HASH_SPECIALIZE(bool)
405 BOOST_HASH_SPECIALIZE(char)
406 BOOST_HASH_SPECIALIZE(signed char)
407 BOOST_HASH_SPECIALIZE(unsigned char)
408 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
409 BOOST_HASH_SPECIALIZE(wchar_t)
411 BOOST_HASH_SPECIALIZE(short)
412 BOOST_HASH_SPECIALIZE(unsigned short)
413 BOOST_HASH_SPECIALIZE(int)
414 BOOST_HASH_SPECIALIZE(unsigned int)
415 BOOST_HASH_SPECIALIZE(long)
416 BOOST_HASH_SPECIALIZE(unsigned long)
418 BOOST_HASH_SPECIALIZE(float)
419 BOOST_HASH_SPECIALIZE(double)
420 BOOST_HASH_SPECIALIZE(long double)
422 BOOST_HASH_SPECIALIZE_REF(std::string)
423 #if !defined(BOOST_NO_STD_WSTRING)
424 BOOST_HASH_SPECIALIZE_REF(std::wstring)
427 #if !defined(BOOST_NO_LONG_LONG)
428 BOOST_HASH_SPECIALIZE(boost::long_long_type)
429 BOOST_HASH_SPECIALIZE(boost::ulong_long_type)
432 #undef BOOST_HASH_SPECIALIZE
433 #undef BOOST_HASH_SPECIALIZE_REF
435 // Specializing boost::hash for pointers.
437 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
441 : public std::unary_function<T*, std::size_t>
443 std::size_t operator()(T* v) const
445 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590)
446 return boost::hash_value(v);
448 std::size_t x = static_cast<std::size_t>(
449 reinterpret_cast<std::ptrdiff_t>(v));
458 // For compilers without partial specialization, we define a
459 // boost::hash for all remaining types. But hash_impl is only defined
460 // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS
461 // is defined there will still be a compile error for types not supported
464 namespace hash_detail
466 template <bool IsPointer>
470 struct hash_impl<true>
474 : public std::unary_function<T, std::size_t>
476 std::size_t operator()(T val) const
478 #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590)
479 return boost::hash_value(val);
481 std::size_t x = static_cast<std::size_t>(
482 reinterpret_cast<std::ptrdiff_t>(val));
491 template <class T> struct hash
492 : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value>
493 ::BOOST_NESTED_TEMPLATE inner<T>
500 #undef BOOST_HASH_CHAR_TRAITS
502 #endif // BOOST_FUNCTIONAL_HASH_HASH_HPP
504 // Include this outside of the include guards in case the file is included
505 // twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it
508 #if !defined(BOOST_HASH_NO_EXTENSIONS) \
509 && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP)
510 #include <boost/functional/hash/extensions.hpp>