Home | History | Annotate | Download | only in internal
      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 (at) 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