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OgreSmallVector.h @ 153

Last change on this file since 153 was 148, checked in by patricwi, 6 years ago
Added new dependencies for ogre1.9 and cegui0.8
File size: 26.4 KB

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1	//===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------- C++ --===//
2	//
3	// The LLVM Compiler Infrastructure
4	//
5	// This file is distributed under the University of Illinois Open Source
6	// License.
7	// ==============================================================================
8	// LLVM Release License
9	// ==============================================================================
10	// University of Illinois/NCSA
11	// Open Source License
12	//
13	// Copyright (c) 2003-2010 University of Illinois at Urbana-Champaign.
14	// All rights reserved.
15	//
16	// Developed by:
17	//
18	// LLVM Team
19	//
20	// University of Illinois at Urbana-Champaign
21	//
22	// http://llvm.org
23	//
24	// Permission is hereby granted, free of charge, to any person obtaining a copy of
25	// this software and associated documentation files (the "Software"), to deal with
26	// the Software without restriction, including without limitation the rights to
27	// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
28	// of the Software, and to permit persons to whom the Software is furnished to do
29	// so, subject to the following conditions:
30	//
31	// * Redistributions of source code must retain the above copyright notice,
32	// this list of conditions and the following disclaimers.
33	//
34	// * Redistributions in binary form must reproduce the above copyright notice,
35	// this list of conditions and the following disclaimers in the
36	// documentation and/or other materials provided with the distribution.
37	//
38	// * Neither the names of the LLVM Team, University of Illinois at
39	// Urbana-Champaign, nor the names of its contributors may be used to
40	// endorse or promote products derived from this Software without specific
41	// prior written permission.
42	//
43	// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
44	// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
45	// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
46	// CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
47	// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
48	// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
49	// SOFTWARE.
50	//
51	//===----------------------------------------------------------------------===//
52	//
53	// This file defines the SmallVector class.
54	//
55	//===----------------------------------------------------------------------===//
56
57	#ifndef __SmallVector_H
58	#define __SmallVector_H
59
60	#include <algorithm>
61	#include <cassert>
62	#include <cstddef>
63	#include <cstdlib>
64	#include <cstring>
65	#include <iterator>
66	#include <memory>
67
68	#ifdef _MSC_VER
69	namespace std {
70	#if _MSC_VER <= 1310
71	// Work around flawed VC++ implementation of std::uninitialized_copy. Define
72	// additional overloads so that elements with pointer types are recognized as
73	// scalars and not objects, causing bizarre type conversion errors.
74	template<class T1, class T2>
75	inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 , T2 ) {
76	_Scalar_ptr_iterator_tag _Cat;
77	return _Cat;
78	}
79
80	template<class T1, class T2>
81	inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const , T2 *) {
82	_Scalar_ptr_iterator_tag _Cat;
83	return _Cat;
84	}
85	#else
86	// FIXME: It is not clear if the problem is fixed in VS 2005. What is clear
87	// is that the above hack won't work if it wasn't fixed.
88	#endif
89	}
90	#endif
91
92	namespace Ogre {
93
94	// some type traits
95	template <typename T> struct isPodLike { static const bool value = false; };
96
97	template <> struct isPodLike<bool> { static const bool value = true; };
98	template <> struct isPodLike<char> { static const bool value = true; };
99	template <> struct isPodLike<signed char> { static const bool value = true; };
100	template <> struct isPodLike<unsigned char> { static const bool value = true; };
101	template <> struct isPodLike<int> { static const bool value = true; };
102	template <> struct isPodLike<unsigned> { static const bool value = true; };
103	template <> struct isPodLike<short> { static const bool value = true; };
104	template <> struct isPodLike<unsigned short> { static const bool value = true; };
105	template <> struct isPodLike<long> { static const bool value = true; };
106	template <> struct isPodLike<unsigned long> { static const bool value = true; };
107	template <> struct isPodLike<float> { static const bool value = true; };
108	template <> struct isPodLike<double> { static const bool value = true; };
109	template <typename T> struct isPodLike<T*> { static const bool value = true; };
110
111	template<typename T, typename U>
112	struct isPodLike<std::pair<T, U> > { static const bool value = isPodLike<T>::value & isPodLike<U>::value; };
113
114	/// SmallVectorBase - This is all the non-templated stuff common to all
115	/// SmallVectors.
116	class SmallVectorBase {
117	protected:
118	void BeginX, EndX, *CapacityX;
119
120	// Allocate raw space for N elements of type T. If T has a ctor or dtor, we
121	// don't want it to be automatically run, so we need to represent the space as
122	// something else. An array of char would work great, but might not be
123	// aligned sufficiently. Instead we use some number of union instances for
124	// the space, which guarantee maximal alignment.
125	union U {
126	double D;
127	long double LD;
128	long long L;
129	void *P;
130	} FirstEl;
131	// Space after 'FirstEl' is clobbered, do not add any instance vars after it.
132
133	protected:
134	SmallVectorBase(size_t Size)
135	: BeginX(&FirstEl), EndX(&FirstEl), CapacityX((char*)&FirstEl+Size) {}
136
137	/// isSmall - Return true if this is a smallvector which has not had dynamic
138	/// memory allocated for it.
139	bool isSmall() const {
140	return BeginX == static_cast<const void*>(&FirstEl);
141	}
142
143	/// size_in_bytes - This returns size()*sizeof(T).
144	size_t size_in_bytes() const {
145	return size_t((char)EndX - (char)BeginX);
146	}
147
148	/// capacity_in_bytes - This returns capacity()*sizeof(T).
149	size_t capacity_in_bytes() const {
150	return size_t((char)CapacityX - (char)BeginX);
151	}
152
153	/// grow_pod - This is an implementation of the grow() method which only works
154	/// on POD-like data types and is out of line to reduce code duplication.
155	void grow_pod(size_t MinSizeInBytes, size_t TSize);
156
157	public:
158	bool empty() const { return BeginX == EndX; }
159	};
160
161
162	template <typename T>
163	class SmallVectorTemplateCommon : public SmallVectorBase {
164	protected:
165	void setEnd(T *P) { this->EndX = P; }
166	public:
167	SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(Size) {}
168
169	typedef size_t size_type;
170	typedef ptrdiff_t difference_type;
171	typedef T value_type;
172	typedef T *iterator;
173	typedef const T *const_iterator;
174
175	typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
176	typedef std::reverse_iterator<iterator> reverse_iterator;
177
178	typedef T &reference;
179	typedef const T &const_reference;
180	typedef T *pointer;
181	typedef const T *const_pointer;
182
183	// forward iterator creation methods.
184	iterator begin() { return (iterator)this->BeginX; }
185	const_iterator begin() const { return (const_iterator)this->BeginX; }
186	iterator end() { return (iterator)this->EndX; }
187	const_iterator end() const { return (const_iterator)this->EndX; }
188	protected:
189	iterator capacity_ptr() { return (iterator)this->CapacityX; }
190	const_iterator capacity_ptr() const { return (const_iterator)this->CapacityX;}
191	public:
192
193	// reverse iterator creation methods.
194	reverse_iterator rbegin() { return reverse_iterator(end()); }
195	const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
196	reverse_iterator rend() { return reverse_iterator(begin()); }
197	const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
198
199	size_type size() const { return end()-begin(); }
200	size_type max_size() const { return size_type(-1) / sizeof(T); }
201
202	/// capacity - Return the total number of elements in the currently allocated
203	/// buffer.
204	size_t capacity() const { return capacity_ptr() - begin(); }
205
206	/// data - Return a pointer to the vector's buffer, even if empty().
207	pointer data() { return pointer(begin()); }
208	/// data - Return a pointer to the vector's buffer, even if empty().
209	const_pointer data() const { return const_pointer(begin()); }
210
211	reference operator[](unsigned idx) {
212	assert(begin() + idx < end());
213	return begin()[idx];
214	}
215	const_reference operator[](unsigned idx) const {
216	assert(begin() + idx < end());
217	return begin()[idx];
218	}
219
220	reference front() {
221	return begin()[0];
222	}
223	const_reference front() const {
224	return begin()[0];
225	}
226
227	reference back() {
228	return end()[-1];
229	}
230	const_reference back() const {
231	return end()[-1];
232	}
233	};
234
235	/// SmallVectorTemplateBase<isPodLike = false> - This is where we put method
236	/// implementations that are designed to work with non-POD-like T's.
237	template <typename T, bool isPodLike>
238	class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
239	public:
240	SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
241
242	static void destroy_range(T S, T E) {
243	while (S != E) {
244	--E;
245	E->~T();
246	}
247	}
248
249	/// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
250	/// starting with "Dest", constructing elements into it as needed.
251	template<typename It1, typename It2>
252	static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
253	std::uninitialized_copy(I, E, Dest);
254	}
255
256	/// grow - double the size of the allocated memory, guaranteeing space for at
257	/// least one more element or MinSize if specified.
258	void grow(size_t MinSize = 0);
259	};
260
261	// Define this out-of-line to dissuade the C++ compiler from inlining it.
262	template <typename T, bool isPodLike>
263	void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
264	size_t CurCapacity = this->capacity();
265	size_t CurSize = this->size();
266	size_t NewCapacity = 2*CurCapacity + 1; // Always grow, even from zero.
267	if (NewCapacity < MinSize)
268	NewCapacity = MinSize;
269	T NewElts = static_cast<T>(malloc(NewCapacity*sizeof(T)));
270
271	// Copy the elements over.
272	this->uninitialized_copy(this->begin(), this->end(), NewElts);
273
274	// Destroy the original elements.
275	destroy_range(this->begin(), this->end());
276
277	// If this wasn't grown from the inline copy, deallocate the old space.
278	if (!this->isSmall())
279	free(this->begin());
280
281	this->setEnd(NewElts+CurSize);
282	this->BeginX = NewElts;
283	this->CapacityX = this->begin()+NewCapacity;
284	}
285
286
287	/// SmallVectorTemplateBase<isPodLike = true> - This is where we put method
288	/// implementations that are designed to work with POD-like T's.
289	template <typename T>
290	class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> {
291	public:
292	SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
293
294	// No need to do a destroy loop for POD's.
295	static void destroy_range(T , T ) {}
296
297	/// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
298	/// starting with "Dest", constructing elements into it as needed.
299	template<typename It1, typename It2>
300	static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
301	// Arbitrary iterator types; just use the basic implementation.
302	std::uninitialized_copy(I, E, Dest);
303	}
304
305	/// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
306	/// starting with "Dest", constructing elements into it as needed.
307	template<typename T1, typename T2>
308	static void uninitialized_copy(T1 I, T1 E, T2 *Dest) {
309	// Use memcpy for PODs iterated by pointers (which includes SmallVector
310	// iterators): std::uninitialized_copy optimizes to memmove, but we can
311	// use memcpy here.
312	memcpy(Dest, I, (E-I)*sizeof(T));
313	}
314
315	/// grow - double the size of the allocated memory, guaranteeing space for at
316	/// least one more element or MinSize if specified.
317	void grow(size_t MinSize = 0) {
318	this->grow_pod(MinSize*sizeof(T), sizeof(T));
319	}
320	};
321
322
323	/// SmallVectorImpl - This class consists of common code factored out of the
324	/// SmallVector class to reduce code duplication based on the SmallVector 'N'
325	/// template parameter.
326	template <typename T>
327	class SmallVectorImpl : public SmallVectorTemplateBase<T, isPodLike<T>::value> {
328	typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass;
329
330	SmallVectorImpl(const SmallVectorImpl&); // DISABLED.
331	public:
332	typedef typename SuperClass::iterator iterator;
333	typedef typename SuperClass::size_type size_type;
334
335	// Default ctor - Initialize to empty.
336	explicit SmallVectorImpl(unsigned N)
337	: SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) {
338	}
339
340	~SmallVectorImpl() {
341	// Destroy the constructed elements in the vector.
342	this->destroy_range(this->begin(), this->end());
343
344	// If this wasn't grown from the inline copy, deallocate the old space.
345	if (!this->isSmall())
346	free(this->begin());
347	}
348
349
350	void clear() {
351	this->destroy_range(this->begin(), this->end());
352	this->EndX = this->BeginX;
353	}
354
355	void resize(unsigned N) {
356	if (N < this->size()) {
357	this->destroy_range(this->begin()+N, this->end());
358	this->setEnd(this->begin()+N);
359	} else if (N > this->size()) {
360	if (this->capacity() < N)
361	this->grow(N);
362	this->construct_range(this->end(), this->begin()+N, T());
363	this->setEnd(this->begin()+N);
364	}
365	}
366
367	void resize(unsigned N, const T &NV) {
368	if (N < this->size()) {
369	this->destroy_range(this->begin()+N, this->end());
370	this->setEnd(this->begin()+N);
371	} else if (N > this->size()) {
372	if (this->capacity() < N)
373	this->grow(N);
374	construct_range(this->end(), this->begin()+N, NV);
375	this->setEnd(this->begin()+N);
376	}
377	}
378
379	void reserve(unsigned N) {
380	if (this->capacity() < N)
381	this->grow(N);
382	}
383
384	void push_back(const T &Elt) {
385	if (this->EndX < this->CapacityX) {
386	Retry:
387	new (this->end()) T(Elt);
388	this->setEnd(this->end()+1);
389	return;
390	}
391	this->grow();
392	goto Retry;
393	}
394
395	void pop_back() {
396	this->setEnd(this->end()-1);
397	this->end()->~T();
398	}
399
400	T pop_back_val() {
401	T Result = this->back();
402	pop_back();
403	return Result;
404	}
405
406	void swap(SmallVectorImpl &RHS);
407
408	/// append - Add the specified range to the end of the SmallVector.
409	///
410	template<typename in_iter>
411	void append(in_iter in_start, in_iter in_end) {
412	size_type NumInputs = std::distance(in_start, in_end);
413	// Grow allocated space if needed.
414	if (NumInputs > size_type(this->capacity_ptr()-this->end()))
415	this->grow(this->size()+NumInputs);
416
417	// Copy the new elements over.
418	// TODO: NEED To compile time dispatch on whether in_iter is a random access
419	// iterator to use the fast uninitialized_copy.
420	std::uninitialized_copy(in_start, in_end, this->end());
421	this->setEnd(this->end() + NumInputs);
422	}
423
424	/// append - Add the specified range to the end of the SmallVector.
425	///
426	void append(size_type NumInputs, const T &Elt) {
427	// Grow allocated space if needed.
428	if (NumInputs > size_type(this->capacity_ptr()-this->end()))
429	this->grow(this->size()+NumInputs);
430
431	// Copy the new elements over.
432	std::uninitialized_fill_n(this->end(), NumInputs, Elt);
433	this->setEnd(this->end() + NumInputs);
434	}
435
436	void assign(unsigned NumElts, const T &Elt) {
437	clear();
438	if (this->capacity() < NumElts)
439	this->grow(NumElts);
440	this->setEnd(this->begin()+NumElts);
441	construct_range(this->begin(), this->end(), Elt);
442	}
443
444	iterator erase(iterator I) {
445	iterator N = I;
446	// Shift all elts down one.
447	std::copy(I+1, this->end(), I);
448	// Drop the last elt.
449	pop_back();
450	return(N);
451	}
452
453	iterator erase(iterator S, iterator E) {
454	iterator N = S;
455	// Shift all elts down.
456	iterator I = std::copy(E, this->end(), S);
457	// Drop the last elts.
458	this->destroy_range(I, this->end());
459	this->setEnd(I);
460	return(N);
461	}
462
463	iterator insert(iterator I, const T &Elt) {
464	if (I == this->end()) { // Important special case for empty vector.
465	push_back(Elt);
466	return this->end()-1;
467	}
468
469	if (this->EndX < this->CapacityX) {
470	Retry:
471	new (this->end()) T(this->back());
472	this->setEnd(this->end()+1);
473	// Push everything else over.
474	std::copy_backward(I, this->end()-1, this->end());
475	*I = Elt;
476	return I;
477	}
478	size_t EltNo = I-this->begin();
479	this->grow();
480	I = this->begin()+EltNo;
481	goto Retry;
482	}
483
484	iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
485	if (I == this->end()) { // Important special case for empty vector.
486	append(NumToInsert, Elt);
487	return this->end()-1;
488	}
489
490	// Convert iterator to elt# to avoid invalidating iterator when we reserve()
491	size_t InsertElt = I - this->begin();
492
493	// Ensure there is enough space.
494	reserve(static_cast<unsigned>(this->size() + NumToInsert));
495
496	// Uninvalidate the iterator.
497	I = this->begin()+InsertElt;
498
499	// If there are more elements between the insertion point and the end of the
500	// range than there are being inserted, we can use a simple approach to
501	// insertion. Since we already reserved space, we know that this won't
502	// reallocate the vector.
503	if (size_t(this->end()-I) >= NumToInsert) {
504	T *OldEnd = this->end();
505	append(this->end()-NumToInsert, this->end());
506
507	// Copy the existing elements that get replaced.
508	std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
509
510	std::fill_n(I, NumToInsert, Elt);
511	return I;
512	}
513
514	// Otherwise, we're inserting more elements than exist already, and we're
515	// not inserting at the end.
516
517	// Copy over the elements that we're about to overwrite.
518	T *OldEnd = this->end();
519	this->setEnd(this->end() + NumToInsert);
520	size_t NumOverwritten = OldEnd-I;
521	this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
522
523	// Replace the overwritten part.
524	std::fill_n(I, NumOverwritten, Elt);
525
526	// Insert the non-overwritten middle part.
527	std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
528	return I;
529	}
530
531	template<typename ItTy>
532	iterator insert(iterator I, ItTy From, ItTy To) {
533	if (I == this->end()) { // Important special case for empty vector.
534	append(From, To);
535	return this->end()-1;
536	}
537
538	size_t NumToInsert = std::distance(From, To);
539	// Convert iterator to elt# to avoid invalidating iterator when we reserve()
540	size_t InsertElt = I - this->begin();
541
542	// Ensure there is enough space.
543	reserve(static_cast<unsigned>(this->size() + NumToInsert));
544
545	// Uninvalidate the iterator.
546	I = this->begin()+InsertElt;
547
548	// If there are more elements between the insertion point and the end of the
549	// range than there are being inserted, we can use a simple approach to
550	// insertion. Since we already reserved space, we know that this won't
551	// reallocate the vector.
552	if (size_t(this->end()-I) >= NumToInsert) {
553	T *OldEnd = this->end();
554	append(this->end()-NumToInsert, this->end());
555
556	// Copy the existing elements that get replaced.
557	std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
558
559	std::copy(From, To, I);
560	return I;
561	}
562
563	// Otherwise, we're inserting more elements than exist already, and we're
564	// not inserting at the end.
565
566	// Copy over the elements that we're about to overwrite.
567	T *OldEnd = this->end();
568	this->setEnd(this->end() + NumToInsert);
569	size_t NumOverwritten = OldEnd-I;
570	this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
571
572	// Replace the overwritten part.
573	for (; NumOverwritten > 0; --NumOverwritten) {
574	I = From;
575	++I; ++From;
576	}
577
578	// Insert the non-overwritten middle part.
579	this->uninitialized_copy(From, To, OldEnd);
580	return I;
581	}
582
583	const SmallVectorImpl
584	&operator=(const SmallVectorImpl &RHS);
585
586	bool operator==(const SmallVectorImpl &RHS) const {
587	if (this->size() != RHS.size()) return false;
588	return std::equal(this->begin(), this->end(), RHS.begin());
589	}
590	bool operator!=(const SmallVectorImpl &RHS) const {
591	return !(*this == RHS);
592	}
593
594	bool operator<(const SmallVectorImpl &RHS) const {
595	return std::lexicographical_compare(this->begin(), this->end(),
596	RHS.begin(), RHS.end());
597	}
598
599	/// set_size - Set the array size to \arg N, which the current array must have
600	/// enough capacity for.
601	///
602	/// This does not construct or destroy any elements in the vector.
603	///
604	/// Clients can use this in conjunction with capacity() to write past the end
605	/// of the buffer when they know that more elements are available, and only
606	/// update the size later. This avoids the cost of value initializing elements
607	/// which will only be overwritten.
608	void set_size(unsigned N) {
609	assert(N <= this->capacity());
610	this->setEnd(this->begin() + N);
611	}
612
613	private:
614	static void construct_range(T S, T E, const T &Elt) {
615	for (; S != E; ++S)
616	new (S) T(Elt);
617	}
618	};
619
620
621	template <typename T>
622	void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) {
623	if (this == &RHS) return;
624
625	// We can only avoid copying elements if neither vector is small.
626	if (!this->isSmall() && !RHS.isSmall()) {
627	std::swap(this->BeginX, RHS.BeginX);
628	std::swap(this->EndX, RHS.EndX);
629	std::swap(this->CapacityX, RHS.CapacityX);
630	return;
631	}
632	if (RHS.size() > this->capacity())
633	this->grow(RHS.size());
634	if (this->size() > RHS.capacity())
635	RHS.grow(this->size());
636
637	// Swap the shared elements.
638	size_t NumShared = this->size();
639	if (NumShared > RHS.size()) NumShared = RHS.size();
640	for (unsigned i = 0; i != static_cast<unsigned>(NumShared); ++i)
641	std::swap((*this)[i], RHS[i]);
642
643	// Copy over the extra elts.
644	if (this->size() > RHS.size()) {
645	size_t EltDiff = this->size() - RHS.size();
646	this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
647	RHS.setEnd(RHS.end()+EltDiff);
648	this->destroy_range(this->begin()+NumShared, this->end());
649	this->setEnd(this->begin()+NumShared);
650	} else if (RHS.size() > this->size()) {
651	size_t EltDiff = RHS.size() - this->size();
652	this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
653	this->setEnd(this->end() + EltDiff);
654	this->destroy_range(RHS.begin()+NumShared, RHS.end());
655	RHS.setEnd(RHS.begin()+NumShared);
656	}
657	}
658
659	template <typename T>
660	const SmallVectorImpl<T> &SmallVectorImpl<T>::
661	operator=(const SmallVectorImpl<T> &RHS) {
662	// Avoid self-assignment.
663	if (this == &RHS) return *this;
664
665	// If we already have sufficient space, assign the common elements, then
666	// destroy any excess.
667	size_t RHSSize = RHS.size();
668	size_t CurSize = this->size();
669	if (CurSize >= RHSSize) {
670	// Assign common elements.
671	iterator NewEnd;
672	if (RHSSize)
673	NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
674	else
675	NewEnd = this->begin();
676
677	// Destroy excess elements.
678	this->destroy_range(NewEnd, this->end());
679
680	// Trim.
681	this->setEnd(NewEnd);
682	return *this;
683	}
684
685	// If we have to grow to have enough elements, destroy the current elements.
686	// This allows us to avoid copying them during the grow.
687	if (this->capacity() < RHSSize) {
688	// Destroy current elements.
689	this->destroy_range(this->begin(), this->end());
690	this->setEnd(this->begin());
691	CurSize = 0;
692	this->grow(RHSSize);
693	} else if (CurSize) {
694	// Otherwise, use assignment for the already-constructed elements.
695	std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
696	}
697
698	// Copy construct the new elements in place.
699	this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
700	this->begin()+CurSize);
701
702	// Set end.
703	this->setEnd(this->begin()+RHSSize);
704	return *this;
705	}
706
707
708	/// SmallVector - This is a 'vector' (really, a variable-sized array), optimized
709	/// for the case when the array is small. It contains some number of elements
710	/// in-place, which allows it to avoid heap allocation when the actual number of
711	/// elements is below that threshold. This allows normal "small" cases to be
712	/// fast without losing generality for large inputs.
713	///
714	/// Note that this does not attempt to be exception safe.
715	///
716	template <typename T, unsigned N>
717	class SmallVector : public SmallVectorImpl<T> {
718	/// InlineElts - These are 'N-1' elements that are stored inline in the body
719	/// of the vector. The extra '1' element is stored in SmallVectorImpl.
720	typedef typename SmallVectorImpl<T>::U U;
721	enum {
722	// MinUs - The number of U's require to cover N T's.
723	MinUs = (static_cast<unsigned int>(sizeof(T))*N +
724	static_cast<unsigned int>(sizeof(U)) - 1) /
725	static_cast<unsigned int>(sizeof(U)),
726
727	// NumInlineEltsElts - The number of elements actually in this array. There
728	// is already one in the parent class, and we have to round up to avoid
729	// having a zero-element array.
730	NumInlineEltsElts = MinUs > 1 ? (MinUs - 1) : 1,
731
732	// NumTsAvailable - The number of T's we actually have space for, which may
733	// be more than N due to rounding.
734	NumTsAvailable = (NumInlineEltsElts+1)*static_cast<unsigned int>(sizeof(U))/
735	static_cast<unsigned int>(sizeof(T))
736	};
737	U InlineElts[NumInlineEltsElts];
738	public:
739	SmallVector() : SmallVectorImpl<T>(NumTsAvailable) {
740	}
741
742	explicit SmallVector(unsigned Size, const T &Value = T())
743	: SmallVectorImpl<T>(NumTsAvailable) {
744	this->reserve(Size);
745	while (Size--)
746	this->push_back(Value);
747	}
748
749	template<typename ItTy>
750	SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(NumTsAvailable) {
751	this->append(S, E);
752	}
753
754	SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(NumTsAvailable) {
755	if (!RHS.empty())
756	SmallVectorImpl<T>::operator=(RHS);
757	}
758
759	const SmallVector &operator=(const SmallVector &RHS) {
760	SmallVectorImpl<T>::operator=(RHS);
761	return *this;
762	}
763
764	};
765
766	/// Specialize SmallVector at N=0. This specialization guarantees
767	/// that it can be instantiated at an incomplete T if none of its
768	/// members are required.
769	template <typename T>
770	class SmallVector<T,0> : public SmallVectorImpl<T> {
771	public:
772	SmallVector() : SmallVectorImpl<T>(0) {}
773
774	explicit SmallVector(unsigned Size, const T &Value = T())
775	: SmallVectorImpl<T>(0) {
776	this->reserve(Size);
777	while (Size--)
778	this->push_back(Value);
779	}
780
781	template<typename ItTy>
782	SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(0) {
783	this->append(S, E);
784	}
785
786	SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(0) {
787	SmallVectorImpl<T>::operator=(RHS);
788	}
789
790	SmallVector &operator=(const SmallVectorImpl<T> &RHS) {
791	return SmallVectorImpl<T>::operator=(RHS);
792	}
793
794	};
795
796	} // End Ogre namespace
797
798	namespace std {
799	/// Implement std::swap in terms of SmallVector swap.
800	template<typename T>
801	inline void
802	swap(Ogre::SmallVectorImpl<T> &LHS, Ogre::SmallVectorImpl<T> &RHS) {
803	LHS.swap(RHS);
804	}
805
806	/// Implement std::swap in terms of SmallVector swap.
807	template<typename T, unsigned N>
808	inline void
809	swap(Ogre::SmallVector<T, N> &LHS, Ogre::SmallVector<T, N> &RHS) {
810	LHS.swap(RHS);
811	}
812	}
813
814	#endif

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source: downloads/ogre_src_v1-9-0/OgreMain/include/OgreSmallVector.h @ 153

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