1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#ifndef WTF_VectorTraits_h
22#define WTF_VectorTraits_h
23
24#include "OwnPtr.h"
25#include "RefPtr.h"
26#include "TypeTraits.h"
27#include <utility>
28#include <memory>
29
30using std::pair;
31
32namespace WTF {
33
34 template<bool isPod, typename T>
35 struct VectorTraitsBase;
36
37 template<typename T>
38 struct VectorTraitsBase<false, T>
39 {
40 static const bool needsDestruction = true;
41 static const bool needsInitialization = true;
42 static const bool canInitializeWithMemset = false;
43 static const bool canMoveWithMemcpy = false;
44 static const bool canCopyWithMemcpy = false;
45 static const bool canFillWithMemset = false;
46 static const bool canCompareWithMemcmp = false;
47 };
48
49 template<typename T>
50 struct VectorTraitsBase<true, T>
51 {
52 static const bool needsDestruction = false;
53 static const bool needsInitialization = false;
54 static const bool canInitializeWithMemset = false;
55 static const bool canMoveWithMemcpy = true;
56 static const bool canCopyWithMemcpy = true;
57 static const bool canFillWithMemset = sizeof(T) == sizeof(char);
58 static const bool canCompareWithMemcmp = true;
59 };
60
61 template<typename T>
62 struct VectorTraits : VectorTraitsBase<IsPod<T>::value, T> { };
63
64 struct SimpleClassVectorTraits
65 {
66 static const bool needsDestruction = true;
67 static const bool needsInitialization = true;
68 static const bool canInitializeWithMemset = true;
69 static const bool canMoveWithMemcpy = true;
70 static const bool canCopyWithMemcpy = false;
71 static const bool canFillWithMemset = false;
72 static const bool canCompareWithMemcmp = true;
73 };
74
75 // we know OwnPtr and RefPtr are simple enough that initializing to 0 and moving with memcpy
76 // (and then not destructing the original) will totally work
77 template<typename P>
78 struct VectorTraits<RefPtr<P> > : SimpleClassVectorTraits { };
79
80 template<typename P>
81 struct VectorTraits<OwnPtr<P> > : SimpleClassVectorTraits { };
82
83 template<typename P>
84 struct VectorTraits<std::auto_ptr<P> > : SimpleClassVectorTraits { };
85
86 template<typename First, typename Second>
87 struct VectorTraits<pair<First, Second> >
88 {
89 typedef VectorTraits<First> FirstTraits;
90 typedef VectorTraits<Second> SecondTraits;
91
92 static const bool needsDestruction = FirstTraits::needsDestruction || SecondTraits::needsDestruction;
93 static const bool needsInitialization = FirstTraits::needsInitialization || SecondTraits::needsInitialization;
94 static const bool canInitializeWithMemset = FirstTraits::canInitializeWithMemset && SecondTraits::canInitializeWithMemset;
95 static const bool canMoveWithMemcpy = FirstTraits::canMoveWithMemcpy && SecondTraits::canMoveWithMemcpy;
96 static const bool canCopyWithMemcpy = FirstTraits::canCopyWithMemcpy && SecondTraits::canCopyWithMemcpy;
97 static const bool canFillWithMemset = false;
98 static const bool canCompareWithMemcmp = FirstTraits::canCompareWithMemcmp && SecondTraits::canCompareWithMemcmp;
99 };
100
101} // namespace WTF
102
103using WTF::VectorTraits;
104using WTF::SimpleClassVectorTraits;
105
106#endif // WTF_VectorTraits_h
107

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/wtf/VectorTraits.h