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 
45 namespace ceres {
46 namespace 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.
55 template<int alignment, int size> struct AlignType { };
56 template<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 
67 CERES_ALIGN_TYPE_TEMPLATE(1);
68 CERES_ALIGN_TYPE_TEMPLATE(2);
69 CERES_ALIGN_TYPE_TEMPLATE(4);
70 CERES_ALIGN_TYPE_TEMPLATE(8);
71 CERES_ALIGN_TYPE_TEMPLATE(16);
72 CERES_ALIGN_TYPE_TEMPLATE(32);
73 CERES_ALIGN_TYPE_TEMPLATE(64);
74 CERES_ALIGN_TYPE_TEMPLATE(128);
75 CERES_ALIGN_TYPE_TEMPLATE(256);
76 CERES_ALIGN_TYPE_TEMPLATE(512);
77 CERES_ALIGN_TYPE_TEMPLATE(1024);
78 CERES_ALIGN_TYPE_TEMPLATE(2048);
79 CERES_ALIGN_TYPE_TEMPLATE(4096);
80 CERES_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 
92 template <typename Type>
93 class 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