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memory.hxx
1/************************************************************************/
2/* */
3/* Copyright 2002-2003 by Ullrich Koethe, Hans Meine */
4/* */
5/* This file is part of the VIGRA computer vision library. */
6/* The VIGRA Website is */
7/* http://hci.iwr.uni-heidelberg.de/vigra/ */
8/* Please direct questions, bug reports, and contributions to */
9/* ullrich.koethe@iwr.uni-heidelberg.de or */
10/* vigra@informatik.uni-hamburg.de */
11/* */
12/* Permission is hereby granted, free of charge, to any person */
13/* obtaining a copy of this software and associated documentation */
14/* files (the "Software"), to deal in the Software without */
15/* restriction, including without limitation the rights to use, */
16/* copy, modify, merge, publish, distribute, sublicense, and/or */
17/* sell copies of the Software, and to permit persons to whom the */
18/* Software is furnished to do so, subject to the following */
19/* conditions: */
20/* */
21/* The above copyright notice and this permission notice shall be */
22/* included in all copies or substantial portions of the */
23/* Software. */
24/* */
25/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
26/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
27/* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
28/* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
29/* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
30/* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
31/* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
32/* OTHER DEALINGS IN THE SOFTWARE. */
33/* */
34/************************************************************************/
35
36#ifndef VIGRA_MEMORY_HXX
37#define VIGRA_MEMORY_HXX
38
39
40#include "config.hxx"
41
42#ifdef VIGRA_SHARED_PTR_IN_TR1
43# include <tr1/memory>
44#else
45# include <memory>
46#endif
47
48#include <cstring>
49#include "metaprogramming.hxx"
50
51 namespace vigra {
52
53 enum SkipInitializationTag { SkipInitialization};
54
55 template<class T>
56 struct CanSkipInitialization
57{
58 typedef typename TypeTraits<T>::isBuiltinType type;
59 static const bool value = type::asBool;
60};
61
62 namespace detail {
63
64// differs from std::uninitialized_copy by explicit type conversion
65 template <class Src, class Dest>
66Dest uninitializedCopy(Src s, Src end, Dest d)
67{
68 typedef typename std::iterator_traits<Dest>::value_type T;
69 for(; s != end; ++s, ++d)
70 new(d) T(static_cast<T const &>(*s));
71 return d;
72}
73
74 template <class T>
75 struct PlacementNewAllocator
76{
77 T * allocate(std::size_t n)
78 {
79 return (T*)::operator new(n*sizeof(T));
80 }
81
82 void deallocate(T * p, std::size_t)
83 {
84 return ::operator delete(p);
85 }
86
87 void construct(T * p, T const & initial)
88 {
89 new(p) T(initial);
90 }
91
92 void destroy(T * p)
93 {
94 p->~T();
95 }
96};
97
98 template <class T>
99 inline void
100destroy_n(T * /* p */, std::size_t /* n */, VigraTrueType /* isPOD */)
101{}
102
103 template <class T>
104 inline void
105destroy_n(T * p, std::size_t n, VigraFalseType /* isPOD */)
106{
107 for(std::size_t i=0; i < n; ++i, ++p)
108 p->~T();
109}
110
111 template <class T>
112 inline void
113destroy_n(T * p, std::size_t n)
114{
115 destroy_n(p, n, typename TypeTraits<T>::isPOD());
116}
117
118 template <class T, class Alloc>
119 inline T *
120alloc_initialize_n(std::size_t n, T const & initial, Alloc & alloc)
121{
122 T * p = alloc.allocate(n);
123 bool useMemset = TypeTraits<T>::isPOD::value &&
124 (initial == T());
125 if(useMemset)
126 {
127 std::memset(p, 0, n*sizeof(T));
128 }
129 else
130 {
131 std::size_t i=0;
132 try
133 {
134 for (; i < n; ++i)
135 alloc.construct(p+i, initial);
136 }
137 catch (...)
138 {
139 for (std::size_t j=0; j < i; ++j)
140 alloc.destroy(p+j);
141 alloc.deallocate(p, n);
142 throw;
143 }
144 }
145 return p;
146}
147
148 template <class T>
149 inline T *
150alloc_initialize_n(std::size_t n, T const & initial)
151{
152 PlacementNewAllocator<T> alloc;
153 return alloc_initialize_n<T>(n, initial, alloc);
154}
155
156 template <class T>
157 inline T *
158alloc_initialize_n(std::size_t n)
159{
160 PlacementNewAllocator<T> alloc;
161 return alloc_initialize_n<T>(n, T(), alloc);
162}
163
164 template <class T, class Alloc>
165 inline void
166destroy_dealloc_impl(T * p, std::size_t n, Alloc & alloc, VigraTrueType /* isPOD */)
167{
168 alloc.deallocate(p, n);
169}
170
171 template <class T, class Alloc>
172 inline void
173destroy_dealloc_impl(T * p, std::size_t n, Alloc & alloc, VigraFalseType /* isPOD */)
174{
175 for (std::size_t i=0; i < n; ++i)
176 alloc.destroy(p + i);
177 alloc.deallocate(p, n);
178}
179
180 template <class T, class Alloc>
181 inline T *
182destroy_dealloc_n(T * p, std::size_t n, Alloc & alloc)
183{
184 if(p != 0)
185 destroy_dealloc_impl(p, n, alloc, typename TypeTraits<T>::isPOD());
186 return 0;
187}
188
189 template <class T>
190 inline T *
191destroy_dealloc_n(T * p, std::size_t n)
192{
193 if(p != 0)
194 {
195 PlacementNewAllocator<T> alloc;
196 destroy_dealloc_impl(p, n, alloc, typename TypeTraits<T>::isPOD());
197 }
198 return 0;
199}
200
201/********************************************************************/
202
203// g++ 2.95 has std::destroy() in the STL
204#if !defined(__GNUC__) || __GNUC__ >= 3
205
206 template <class T>
207 inline void destroy(T * /* p */, VigraTrueType /* isPOD */)
208{
209}
210
211 template <class T>
212 inline void destroy(T * p, VigraFalseType /* isPOD */)
213{
214 p->~T();
215}
216
217 template <class T>
218 inline void destroy(T * p)
219{
220 destroy(p, typename TypeTraits<T>::isPOD());
221}
222
223#else
224
225} } // namespace vigra::detail
226
227#include <memory>
228
229 namespace vigra { namespace detail {
230
231 using std::destroy;
232
233#endif
234
235} } // namespace vigra::detail
236
237#endif // VIGRA_MEMORY_HXX
vigra

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de) Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany | html generated using doxygen and Python vigra 1.11.1