1 // Copyright (C) 2002-2012 Nikolaus Gebhardt
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2 // This file is part of the "Irrlicht Engine" and the "irrXML" project.
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3 // For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
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5 #ifndef __IRR_ARRAY_H_INCLUDED__
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6 #define __IRR_ARRAY_H_INCLUDED__
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8 #include "irrTypes.h"
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9 #include "heapsort.h"
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10 #include "irrAllocator.h"
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11 #include "irrMath.h"
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18 //! Self reallocating template array (like stl vector) with additional features.
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19 /** Some features are: Heap sorting, binary search methods, easier debugging.
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21 template <class T, typename TAlloc = irrAllocator<T> >
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27 //! Default constructor for empty array.
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28 array() : data(0), allocated(0), used(0),
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29 strategy(ALLOC_STRATEGY_DOUBLE), free_when_destroyed(true), is_sorted(true)
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34 //! Constructs an array and allocates an initial chunk of memory.
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35 /** \param start_count Amount of elements to pre-allocate. */
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36 explicit array(u32 start_count) : data(0), allocated(0), used(0),
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37 strategy(ALLOC_STRATEGY_DOUBLE),
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38 free_when_destroyed(true), is_sorted(true)
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40 reallocate(start_count);
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44 //! Copy constructor
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45 array(const array<T, TAlloc>& other) : data(0)
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52 /** Frees allocated memory, if set_free_when_destroyed was not set to
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53 false by the user before. */
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60 //! Reallocates the array, make it bigger or smaller.
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61 /** \param new_size New size of array.
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62 \param canShrink Specifies whether the array is reallocated even if
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63 enough space is available. Setting this flag to false can speed up
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64 array usage, but may use more memory than required by the data.
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66 void reallocate(u32 new_size, bool canShrink=true)
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68 if (allocated==new_size)
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70 if (!canShrink && (new_size < allocated))
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75 data = allocator.allocate(new_size); //new T[new_size];
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76 allocated = new_size;
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79 const s32 end = used < new_size ? used : new_size;
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81 for (s32 i=0; i<end; ++i)
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83 // data[i] = old_data[i];
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84 allocator.construct(&data[i], old_data[i]);
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87 // destruct old data
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88 for (u32 j=0; j<used; ++j)
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89 allocator.destruct(&old_data[j]);
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91 if (allocated < used)
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94 allocator.deallocate(old_data); //delete [] old_data;
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98 //! set a new allocation strategy
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99 /** if the maximum size of the array is unknown, you can define how big the
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100 allocation should happen.
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101 \param newStrategy New strategy to apply to this array. */
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102 void setAllocStrategy ( eAllocStrategy newStrategy = ALLOC_STRATEGY_DOUBLE )
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104 strategy = newStrategy;
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108 //! Adds an element at back of array.
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109 /** If the array is too small to add this new element it is made bigger.
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110 \param element: Element to add at the back of the array. */
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111 void push_back(const T& element)
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113 insert(element, used);
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117 //! Adds an element at the front of the array.
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118 /** If the array is to small to add this new element, the array is
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119 made bigger. Please note that this is slow, because the whole array
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120 needs to be copied for this.
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121 \param element Element to add at the back of the array. */
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122 void push_front(const T& element)
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128 //! Insert item into array at specified position.
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130 \param element: Element to be inserted
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131 \param index: Where position to insert the new element. */
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132 void insert(const T& element, u32 index=0)
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134 _IRR_DEBUG_BREAK_IF(index>used) // access violation
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136 if (used + 1 > allocated)
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138 // this doesn't work if the element is in the same
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139 // array. So we'll copy the element first to be sure
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140 // we'll get no data corruption
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141 const T e(element);
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143 // increase data block
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145 switch ( strategy )
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147 case ALLOC_STRATEGY_DOUBLE:
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148 newAlloc = used + 5 + (allocated < 500 ? used : used >> 2);
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151 case ALLOC_STRATEGY_SAFE:
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152 newAlloc = used + 1;
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155 reallocate( newAlloc);
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157 // move array content and construct new element
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158 // first move end one up
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159 for (u32 i=used; i>index; --i)
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162 allocator.destruct(&data[i]);
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163 allocator.construct(&data[i], data[i-1]); // data[i] = data[i-1];
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165 // then add new element
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167 allocator.destruct(&data[index]);
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168 allocator.construct(&data[index], e); // data[index] = e;
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172 // element inserted not at end
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173 if ( used > index )
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175 // create one new element at the end
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176 allocator.construct(&data[used], data[used-1]);
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178 // move the rest of the array content
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179 for (u32 i=used-1; i>index; --i)
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181 data[i] = data[i-1];
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183 // insert the new element
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184 data[index] = element;
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188 // insert the new element to the end
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189 allocator.construct(&data[index], element);
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192 // set to false as we don't know if we have the comparison operators
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198 //! Clears the array and deletes all allocated memory.
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201 if (free_when_destroyed)
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203 for (u32 i=0; i<used; ++i)
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204 allocator.destruct(&data[i]);
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206 allocator.deallocate(data); // delete [] data;
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215 //! Sets pointer to new array, using this as new workspace.
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216 /** Make sure that set_free_when_destroyed is used properly.
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217 \param newPointer: Pointer to new array of elements.
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218 \param size: Size of the new array.
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219 \param _is_sorted Flag which tells whether the new array is already
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221 \param _free_when_destroyed Sets whether the new memory area shall be
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222 freed by the array upon destruction, or if this will be up to the user
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224 void set_pointer(T* newPointer, u32 size, bool _is_sorted=false, bool _free_when_destroyed=true)
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230 is_sorted = _is_sorted;
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231 free_when_destroyed=_free_when_destroyed;
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235 //! Sets if the array should delete the memory it uses upon destruction.
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236 /** Also clear and set_pointer will only delete the (original) memory
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237 area if this flag is set to true, which is also the default. The
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238 methods reallocate, set_used, push_back, push_front, insert, and erase
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239 will still try to deallocate the original memory, which might cause
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240 troubles depending on the intended use of the memory area.
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241 \param f If true, the array frees the allocated memory in its
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242 destructor, otherwise not. The default is true. */
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243 void set_free_when_destroyed(bool f)
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245 free_when_destroyed = f;
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249 //! Sets the size of the array and allocates new elements if necessary.
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250 /** Please note: This is only secure when using it with simple types,
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251 because no default constructor will be called for the added elements.
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252 \param usedNow Amount of elements now used. */
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253 void set_used(u32 usedNow)
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255 if (allocated < usedNow)
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256 reallocate(usedNow);
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262 //! Assignment operator
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263 const array<T, TAlloc>& operator=(const array<T, TAlloc>& other)
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265 if (this == &other)
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267 strategy = other.strategy;
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272 //if (allocated < other.allocated)
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273 if (other.allocated == 0)
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276 data = allocator.allocate(other.allocated); // new T[other.allocated];
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279 free_when_destroyed = true;
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280 is_sorted = other.is_sorted;
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281 allocated = other.allocated;
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283 for (u32 i=0; i<other.used; ++i)
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284 allocator.construct(&data[i], other.data[i]); // data[i] = other.data[i];
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290 //! Equality operator
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291 bool operator == (const array<T, TAlloc>& other) const
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293 if (used != other.used)
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296 for (u32 i=0; i<other.used; ++i)
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297 if (data[i] != other[i])
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303 //! Inequality operator
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304 bool operator != (const array<T, TAlloc>& other) const
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306 return !(*this==other);
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310 //! Direct access operator
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311 T& operator [](u32 index)
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313 _IRR_DEBUG_BREAK_IF(index>=used) // access violation
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315 return data[index];
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319 //! Direct const access operator
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320 const T& operator [](u32 index) const
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322 _IRR_DEBUG_BREAK_IF(index>=used) // access violation
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324 return data[index];
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328 //! Gets last element.
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331 _IRR_DEBUG_BREAK_IF(!used) // access violation
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333 return data[used-1];
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337 //! Gets last element
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338 const T& getLast() const
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340 _IRR_DEBUG_BREAK_IF(!used) // access violation
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342 return data[used-1];
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346 //! Gets a pointer to the array.
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347 /** \return Pointer to the array. */
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354 //! Gets a const pointer to the array.
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355 /** \return Pointer to the array. */
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356 const T* const_pointer() const
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362 //! Get number of occupied elements of the array.
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363 /** \return Size of elements in the array which are actually occupied. */
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370 //! Get amount of memory allocated.
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371 /** \return Amount of memory allocated. The amount of bytes
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372 allocated would be allocated_size() * sizeof(ElementTypeUsed); */
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373 u32 allocated_size() const
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379 //! Check if array is empty.
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380 /** \return True if the array is empty false if not. */
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387 //! Sorts the array using heapsort.
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388 /** There is no additional memory waste and the algorithm performs
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389 O(n*log n) in worst case. */
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392 if (!is_sorted && used>1)
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393 heapsort(data, used);
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398 //! Performs a binary search for an element, returns -1 if not found.
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399 /** The array will be sorted before the binary search if it is not
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400 already sorted. Caution is advised! Be careful not to call this on
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401 unsorted const arrays, or the slower method will be used.
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402 \param element Element to search for.
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403 \return Position of the searched element if it was found,
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404 otherwise -1 is returned. */
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405 s32 binary_search(const T& element)
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408 return binary_search(element, 0, used-1);
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412 //! Performs a binary search for an element if possible, returns -1 if not found.
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413 /** This method is for const arrays and so cannot call sort(), if the array is
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414 not sorted then linear_search will be used instead. Potentially very slow!
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415 \param element Element to search for.
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416 \return Position of the searched element if it was found,
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417 otherwise -1 is returned. */
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418 s32 binary_search(const T& element) const
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421 return binary_search(element, 0, used-1);
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423 return linear_search(element);
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427 //! Performs a binary search for an element, returns -1 if not found.
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428 /** \param element: Element to search for.
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429 \param left First left index
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430 \param right Last right index.
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431 \return Position of the searched element if it was found, otherwise -1
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433 s32 binary_search(const T& element, s32 left, s32 right) const
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442 m = (left+right)>>1;
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444 if (element < data[m])
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449 } while((element < data[m] || data[m] < element) && left<=right);
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450 // this last line equals to:
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451 // " while((element != array[m]) && left<=right);"
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452 // but we only want to use the '<' operator.
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453 // the same in next line, it is "(element == array[m])"
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456 if (!(element < data[m]) && !(data[m] < element))
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463 //! Performs a binary search for an element, returns -1 if not found.
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464 //! it is used for searching a multiset
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465 /** The array will be sorted before the binary search if it is not
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467 \param element Element to search for.
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468 \param &last return lastIndex of equal elements
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469 \return Position of the first searched element if it was found,
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470 otherwise -1 is returned. */
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471 s32 binary_search_multi(const T& element, s32 &last)
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474 s32 index = binary_search(element, 0, used-1);
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478 // The search can be somewhere in the middle of the set
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479 // look linear previous and past the index
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482 while ( index > 0 && !(element < data[index - 1]) && !(data[index - 1] < element) )
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487 while ( last < (s32) used - 1 && !(element < data[last + 1]) && !(data[last + 1] < element) )
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496 //! Finds an element in linear time, which is very slow.
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497 /** Use binary_search for faster finding. Only works if ==operator is
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499 \param element Element to search for.
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500 \return Position of the searched element if it was found, otherwise -1
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502 s32 linear_search(const T& element) const
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504 for (u32 i=0; i<used; ++i)
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505 if (element == data[i])
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512 //! Finds an element in linear time, which is very slow.
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513 /** Use binary_search for faster finding. Only works if ==operator is
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515 \param element: Element to search for.
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516 \return Position of the searched element if it was found, otherwise -1
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518 s32 linear_reverse_search(const T& element) const
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520 for (s32 i=used-1; i>=0; --i)
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521 if (data[i] == element)
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528 //! Erases an element from the array.
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529 /** May be slow, because all elements following after the erased
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530 element have to be copied.
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531 \param index: Index of element to be erased. */
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532 void erase(u32 index)
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534 _IRR_DEBUG_BREAK_IF(index>=used) // access violation
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536 for (u32 i=index+1; i<used; ++i)
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538 allocator.destruct(&data[i-1]);
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539 allocator.construct(&data[i-1], data[i]); // data[i-1] = data[i];
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542 allocator.destruct(&data[used-1]);
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548 //! Erases some elements from the array.
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549 /** May be slow, because all elements following after the erased
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550 element have to be copied.
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551 \param index: Index of the first element to be erased.
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552 \param count: Amount of elements to be erased. */
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553 void erase(u32 index, s32 count)
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555 if (index>=used || count<1)
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557 if (index+count>used)
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558 count = used-index;
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561 for (i=index; i<index+count; ++i)
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562 allocator.destruct(&data[i]);
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564 for (i=index+count; i<used; ++i)
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566 if (i-count >= index+count) // not already destructed before loop
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567 allocator.destruct(&data[i-count]);
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569 allocator.construct(&data[i-count], data[i]); // data[i-count] = data[i];
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571 if (i >= used-count) // those which are not overwritten
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572 allocator.destruct(&data[i]);
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579 //! Sets if the array is sorted
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580 void set_sorted(bool _is_sorted)
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582 is_sorted = _is_sorted;
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586 //! Swap the content of this array container with the content of another array
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587 /** Afterward this object will contain the content of the other object and the other
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588 object will contain the content of this object.
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589 \param other Swap content with this object */
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590 void swap(array<T, TAlloc>& other)
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592 core::swap(data, other.data);
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593 core::swap(allocated, other.allocated);
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594 core::swap(used, other.used);
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595 core::swap(allocator, other.allocator); // memory is still released by the same allocator used for allocation
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596 eAllocStrategy helper_strategy(strategy); // can't use core::swap with bitfields
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597 strategy = other.strategy;
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598 other.strategy = helper_strategy;
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599 bool helper_free_when_destroyed(free_when_destroyed);
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600 free_when_destroyed = other.free_when_destroyed;
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601 other.free_when_destroyed = helper_free_when_destroyed;
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602 bool helper_is_sorted(is_sorted);
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603 is_sorted = other.is_sorted;
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604 other.is_sorted = helper_is_sorted;
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607 typedef TAlloc allocator_type;
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608 typedef T value_type;
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609 typedef u32 size_type;
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616 eAllocStrategy strategy:4;
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617 bool free_when_destroyed:1;
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622 } // end namespace core
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623 } // end namespace irr
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