1// Ceres Solver - A fast non-linear least squares minimizer
2// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
3// http://code.google.com/p/ceres-solver/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are met:
7//
8// * Redistributions of source code must retain the above copyright notice,
9//   this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above copyright notice,
11//   this list of conditions and the following disclaimer in the documentation
12//   and/or other materials provided with the distribution.
13// * Neither the name of Google Inc. nor the names of its contributors may be
14//   used to endorse or promote products derived from this software without
15//   specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27// POSSIBILITY OF SUCH DAMAGE.
28//
29// Author: kenton@google.com (Kenton Varda)
30//
31// ManualConstructor statically-allocates space in which to store some
32// object, but does not initialize it.  You can then call the constructor
33// and destructor for the object yourself as you see fit.  This is useful
34// for memory management optimizations, where you want to initialize and
35// destroy an object multiple times but only allocate it once.
36//
37// (When I say ManualConstructor statically allocates space, I mean that
38// the ManualConstructor object itself is forced to be the right size.)
39
40#ifndef CERES_PUBLIC_INTERNAL_MANUAL_CONSTRUCTOR_H_
41#define CERES_PUBLIC_INTERNAL_MANUAL_CONSTRUCTOR_H_
42
43#include <new>
44
45namespace ceres {
46namespace internal {
47
48// ------- Define CERES_ALIGNED_CHAR_ARRAY --------------------------------
49
50#ifndef CERES_ALIGNED_CHAR_ARRAY
51
52// Because MSVC and older GCCs require that the argument to their alignment
53// construct to be a literal constant integer, we use a template instantiated
54// at all the possible powers of two.
55template<int alignment, int size> struct AlignType { };
56template<int size> struct AlignType<0, size> { typedef char result[size]; };
57
58#if !defined(CERES_ALIGN_ATTRIBUTE)
59#define CERES_ALIGNED_CHAR_ARRAY you_must_define_CERES_ALIGNED_CHAR_ARRAY_for_your_compiler
60#else  // !defined(CERES_ALIGN_ATTRIBUTE)
61
62#define CERES_ALIGN_TYPE_TEMPLATE(X) \
63  template<int size> struct AlignType<X, size> { \
64    typedef CERES_ALIGN_ATTRIBUTE(X) char result[size]; \
65  }
66
67CERES_ALIGN_TYPE_TEMPLATE(1);
68CERES_ALIGN_TYPE_TEMPLATE(2);
69CERES_ALIGN_TYPE_TEMPLATE(4);
70CERES_ALIGN_TYPE_TEMPLATE(8);
71CERES_ALIGN_TYPE_TEMPLATE(16);
72CERES_ALIGN_TYPE_TEMPLATE(32);
73CERES_ALIGN_TYPE_TEMPLATE(64);
74CERES_ALIGN_TYPE_TEMPLATE(128);
75CERES_ALIGN_TYPE_TEMPLATE(256);
76CERES_ALIGN_TYPE_TEMPLATE(512);
77CERES_ALIGN_TYPE_TEMPLATE(1024);
78CERES_ALIGN_TYPE_TEMPLATE(2048);
79CERES_ALIGN_TYPE_TEMPLATE(4096);
80CERES_ALIGN_TYPE_TEMPLATE(8192);
81// Any larger and MSVC++ will complain.
82
83#undef CERES_ALIGN_TYPE_TEMPLATE
84
85#define CERES_ALIGNED_CHAR_ARRAY(T, Size) \
86  typename AlignType<CERES_ALIGN_OF(T), sizeof(T) * Size>::result
87
88#endif  // !defined(CERES_ALIGN_ATTRIBUTE)
89
90#endif  // CERES_ALIGNED_CHAR_ARRAY
91
92template <typename Type>
93class ManualConstructor {
94 public:
95  // No constructor or destructor because one of the most useful uses of
96  // this class is as part of a union, and members of a union cannot have
97  // constructors or destructors.  And, anyway, the whole point of this
98  // class is to bypass these.
99
100  inline Type* get() {
101    return reinterpret_cast<Type*>(space_);
102  }
103  inline const Type* get() const  {
104    return reinterpret_cast<const Type*>(space_);
105  }
106
107  inline Type* operator->() { return get(); }
108  inline const Type* operator->() const { return get(); }
109
110  inline Type& operator*() { return *get(); }
111  inline const Type& operator*() const { return *get(); }
112
113  // This is needed to get around the strict aliasing warning GCC generates.
114  inline void* space() {
115    return reinterpret_cast<void*>(space_);
116  }
117
118  // You can pass up to four constructor arguments as arguments of Init().
119  inline void Init() {
120    new(space()) Type;
121  }
122
123  template <typename T1>
124  inline void Init(const T1& p1) {
125    new(space()) Type(p1);
126  }
127
128  template <typename T1, typename T2>
129  inline void Init(const T1& p1, const T2& p2) {
130    new(space()) Type(p1, p2);
131  }
132
133  template <typename T1, typename T2, typename T3>
134  inline void Init(const T1& p1, const T2& p2, const T3& p3) {
135    new(space()) Type(p1, p2, p3);
136  }
137
138  template <typename T1, typename T2, typename T3, typename T4>
139  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4) {
140    new(space()) Type(p1, p2, p3, p4);
141  }
142
143  template <typename T1, typename T2, typename T3, typename T4, typename T5>
144  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
145                   const T5& p5) {
146    new(space()) Type(p1, p2, p3, p4, p5);
147  }
148
149  template <typename T1, typename T2, typename T3, typename T4, typename T5,
150            typename T6>
151  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
152                   const T5& p5, const T6& p6) {
153    new(space()) Type(p1, p2, p3, p4, p5, p6);
154  }
155
156  template <typename T1, typename T2, typename T3, typename T4, typename T5,
157            typename T6, typename T7>
158  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
159                   const T5& p5, const T6& p6, const T7& p7) {
160    new(space()) Type(p1, p2, p3, p4, p5, p6, p7);
161  }
162
163  template <typename T1, typename T2, typename T3, typename T4, typename T5,
164            typename T6, typename T7, typename T8>
165  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
166                   const T5& p5, const T6& p6, const T7& p7, const T8& p8) {
167    new(space()) Type(p1, p2, p3, p4, p5, p6, p7, p8);
168  }
169
170  template <typename T1, typename T2, typename T3, typename T4, typename T5,
171            typename T6, typename T7, typename T8, typename T9>
172  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
173                   const T5& p5, const T6& p6, const T7& p7, const T8& p8,
174                   const T9& p9) {
175    new(space()) Type(p1, p2, p3, p4, p5, p6, p7, p8, p9);
176  }
177
178  template <typename T1, typename T2, typename T3, typename T4, typename T5,
179            typename T6, typename T7, typename T8, typename T9, typename T10>
180  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
181                   const T5& p5, const T6& p6, const T7& p7, const T8& p8,
182                   const T9& p9, const T10& p10) {
183    new(space()) Type(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
184  }
185
186  template <typename T1, typename T2, typename T3, typename T4, typename T5,
187            typename T6, typename T7, typename T8, typename T9, typename T10,
188            typename T11>
189  inline void Init(const T1& p1, const T2& p2, const T3& p3, const T4& p4,
190                   const T5& p5, const T6& p6, const T7& p7, const T8& p8,
191                   const T9& p9, const T10& p10, const T11& p11) {
192    new(space()) Type(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11);
193  }
194
195  inline void Destroy() {
196    get()->~Type();
197  }
198
199 private:
200  CERES_ALIGNED_CHAR_ARRAY(Type, 1) space_;
201};
202
203#undef CERES_ALIGNED_CHAR_ARRAY
204
205}  // namespace internal
206}  // namespace ceres
207
208#endif  // CERES_PUBLIC_INTERNAL_MANUAL_CONSTRUCTOR_H_
209