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 | |
30 | using std::pair; |
31 | |
32 | namespace 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 | |
103 | using WTF::VectorTraits; |
104 | using WTF::SimpleClassVectorTraits; |
105 | |
106 | #endif // WTF_VectorTraits_h |
107 | |