// TR1 functional_hash.h header -*- C++ -*-
-// Copyright (C) 2007 Free Software Foundation, Inc.
+// Copyright (C) 2007-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
+// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-// USA.
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
/** @file tr1/functional_hash.h
* This is an internal header file, included by other library headers.
- * You should not attempt to use it directly.
+ * Do not attempt to use it directly. @headername{tr1/functional}
*/
#ifndef _GLIBCXX_TR1_FUNCTIONAL_HASH_H
#pragma GCC system_header
-#if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
-# error TR1 header cannot be included from C++0x header
-#endif
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+namespace tr1
+{
+ /// Class template hash.
+ // Declaration of default hash functor std::tr1::hash. The types for
+ // which std::tr1::hash<T> is well-defined is in clause 6.3.3. of the PDTR.
+ template<typename _Tp>
+ struct hash : public std::unary_function<_Tp, size_t>
+ {
+ size_t
+ operator()(_Tp __val) const;
+ };
+
+ /// Partial specializations for pointer types.
+ template<typename _Tp>
+ struct hash<_Tp*> : public std::unary_function<_Tp*, size_t>
+ {
+ size_t
+ operator()(_Tp* __p) const
+ { return reinterpret_cast<size_t>(__p); }
+ };
+
+ /// Explicit specializations for integer types.
+#define _TR1_hashtable_define_trivial_hash(_Tp) \
+ template<> \
+ inline size_t \
+ hash<_Tp>::operator()(_Tp __val) const \
+ { return static_cast<size_t>(__val); }
+
+ _TR1_hashtable_define_trivial_hash(bool);
+ _TR1_hashtable_define_trivial_hash(char);
+ _TR1_hashtable_define_trivial_hash(signed char);
+ _TR1_hashtable_define_trivial_hash(unsigned char);
+ _TR1_hashtable_define_trivial_hash(wchar_t);
+ _TR1_hashtable_define_trivial_hash(short);
+ _TR1_hashtable_define_trivial_hash(int);
+ _TR1_hashtable_define_trivial_hash(long);
+ _TR1_hashtable_define_trivial_hash(long long);
+ _TR1_hashtable_define_trivial_hash(unsigned short);
+ _TR1_hashtable_define_trivial_hash(unsigned int);
+ _TR1_hashtable_define_trivial_hash(unsigned long);
+ _TR1_hashtable_define_trivial_hash(unsigned long long);
+
+#undef _TR1_hashtable_define_trivial_hash
+
+ // Fowler / Noll / Vo (FNV) Hash (type FNV-1a)
+ // (Used by the next specializations of std::tr1::hash.)
+
+ // N.B. These functions should work on unsigned char, otherwise they do not
+ // correctly implement the FNV-1a algorithm (see PR59406).
+ // The existing behaviour is retained for backwards compatibility.
+
+ /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
+ template<size_t>
+ struct _Fnv_hash_base
+ {
+ template<typename _Tp>
+ static size_t
+ hash(const _Tp* __ptr, size_t __clength)
+ {
+ size_t __result = 0;
+ const char* __cptr = reinterpret_cast<const char*>(__ptr);
+ for (; __clength; --__clength)
+ __result = (__result * 131) + *__cptr++;
+ return __result;
+ }
+ };
+
+ template<>
+ struct _Fnv_hash_base<4>
+ {
+ template<typename _Tp>
+ static size_t
+ hash(const _Tp* __ptr, size_t __clength)
+ {
+ size_t __result = static_cast<size_t>(2166136261UL);
+ const char* __cptr = reinterpret_cast<const char*>(__ptr);
+ for (; __clength; --__clength)
+ {
+ __result ^= static_cast<size_t>(*__cptr++);
+ __result *= static_cast<size_t>(16777619UL);
+ }
+ return __result;
+ }
+ };
+
+ template<>
+ struct _Fnv_hash_base<8>
+ {
+ template<typename _Tp>
+ static size_t
+ hash(const _Tp* __ptr, size_t __clength)
+ {
+ size_t __result
+ = static_cast<size_t>(14695981039346656037ULL);
+ const char* __cptr = reinterpret_cast<const char*>(__ptr);
+ for (; __clength; --__clength)
+ {
+ __result ^= static_cast<size_t>(*__cptr++);
+ __result *= static_cast<size_t>(1099511628211ULL);
+ }
+ return __result;
+ }
+ };
-#if defined(_GLIBCXX_INCLUDE_AS_TR1)
-# include <tr1_impl/functional_hash.h>
-#else
-# define _GLIBCXX_INCLUDE_AS_TR1
-# define _GLIBCXX_BEGIN_NAMESPACE_TR1 namespace tr1 {
-# define _GLIBCXX_END_NAMESPACE_TR1 }
-# define _GLIBCXX_TR1 tr1::
-# include <tr1_impl/functional_hash.h>
-# undef _GLIBCXX_TR1
-# undef _GLIBCXX_END_NAMESPACE_TR1
-# undef _GLIBCXX_BEGIN_NAMESPACE_TR1
-# undef _GLIBCXX_INCLUDE_AS_TR1
+ struct _Fnv_hash
+ : public _Fnv_hash_base<sizeof(size_t)>
+ {
+ using _Fnv_hash_base<sizeof(size_t)>::hash;
+
+ template<typename _Tp>
+ static size_t
+ hash(const _Tp& __val)
+ { return hash(&__val, sizeof(__val)); }
+ };
+
+ /// Explicit specializations for float.
+ template<>
+ inline size_t
+ hash<float>::operator()(float __val) const
+ {
+ // 0 and -0 both hash to zero.
+ return __val != 0.0f ? std::tr1::_Fnv_hash::hash(__val) : 0;
+ }
+
+ /// Explicit specializations for double.
+ template<>
+ inline size_t
+ hash<double>::operator()(double __val) const
+ {
+ // 0 and -0 both hash to zero.
+ return __val != 0.0 ? std::tr1::_Fnv_hash::hash(__val) : 0;
+ }
+
+ /// Explicit specializations for long double.
+ template<>
+ _GLIBCXX_PURE size_t
+ hash<long double>::operator()(long double __val) const;
+
+ /// Explicit specialization of member operator for non-builtin types.
+ template<>
+ _GLIBCXX_PURE size_t
+ hash<string>::operator()(string) const;
+
+ template<>
+ _GLIBCXX_PURE size_t
+ hash<const string&>::operator()(const string&) const;
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+ template<>
+ _GLIBCXX_PURE size_t
+ hash<wstring>::operator()(wstring) const;
+
+ template<>
+ _GLIBCXX_PURE size_t
+ hash<const wstring&>::operator()(const wstring&) const;
#endif
+}
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
#endif // _GLIBCXX_TR1_FUNCTIONAL_HASH_H
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