| /* |
| * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #ifndef WTF_VectorTraits_h |
| #define WTF_VectorTraits_h |
| |
| #include "wtf/OwnPtr.h" |
| #include "wtf/RefPtr.h" |
| #include "wtf/TypeTraits.h" |
| #include <utility> |
| |
| using std::pair; |
| |
| namespace WTF { |
| |
| class AtomicString; |
| |
| template<typename T> |
| struct VectorTraitsBase |
| { |
| static const bool needsDestruction = !IsTriviallyDestructible<T>::value; |
| static const bool canInitializeWithMemset = IsTriviallyDefaultConstructible<T>::value; |
| static const bool canMoveWithMemcpy = IsTriviallyMoveAssignable<T>::value; |
| static const bool canCopyWithMemcpy = IsTriviallyCopyAssignable<T>::value; |
| static const bool canFillWithMemset = IsTriviallyDefaultConstructible<T>::value && (sizeof(T) == sizeof(char)); |
| static const bool canCompareWithMemcmp = IsScalar<T>::value; // Types without padding. |
| template<typename U = void> |
| struct NeedsTracingLazily { |
| static const bool value = NeedsTracing<T>::value; |
| }; |
| static const WeakHandlingFlag weakHandlingFlag = NoWeakHandlingInCollections; // We don't support weak handling in vectors. |
| }; |
| |
| template<typename T> |
| struct VectorTraits : VectorTraitsBase<T> { }; |
| |
| // Classes marked with SimpleVectorTraits will use memmov, memcpy, memcmp |
| // instead of constructors, copy operators, etc for initialization, move |
| // and comparison. |
| template<typename T> |
| struct SimpleClassVectorTraits : VectorTraitsBase<T> |
| { |
| static const bool canInitializeWithMemset = true; |
| static const bool canMoveWithMemcpy = true; |
| static const bool canCompareWithMemcmp = true; |
| }; |
| |
| // We know OwnPtr and RefPtr are simple enough that initializing to 0 and |
| // moving with memcpy (and then not destructing the original) will totally |
| // work. |
| template<typename P> |
| struct VectorTraits<RefPtr<P> > : SimpleClassVectorTraits<RefPtr<P> > { }; |
| |
| template<typename P> |
| struct VectorTraits<OwnPtr<P> > : SimpleClassVectorTraits<OwnPtr<P> > { |
| // OwnPtr -> PassOwnPtr has a very particular structure that |
| // tricks the normal type traits into thinking that the class |
| // is "trivially copyable". |
| static const bool canCopyWithMemcpy = false; |
| }; |
| COMPILE_ASSERT(VectorTraits<RefPtr<int> >::canInitializeWithMemset, inefficientRefPtrVector); |
| COMPILE_ASSERT(VectorTraits<RefPtr<int> >::canMoveWithMemcpy, inefficientRefPtrVector); |
| COMPILE_ASSERT(VectorTraits<RefPtr<int> >::canCompareWithMemcmp, inefficientRefPtrVector); |
| COMPILE_ASSERT(VectorTraits<OwnPtr<int> >::canInitializeWithMemset, inefficientOwnPtrVector); |
| COMPILE_ASSERT(VectorTraits<OwnPtr<int> >::canMoveWithMemcpy, inefficientOwnPtrVector); |
| COMPILE_ASSERT(VectorTraits<OwnPtr<int> >::canCompareWithMemcmp, inefficientOwnPtrVector); |
| |
| template<typename First, typename Second> |
| struct VectorTraits<pair<First, Second> > |
| { |
| typedef VectorTraits<First> FirstTraits; |
| typedef VectorTraits<Second> SecondTraits; |
| |
| static const bool needsDestruction = FirstTraits::needsDestruction || SecondTraits::needsDestruction; |
| static const bool canInitializeWithMemset = FirstTraits::canInitializeWithMemset && SecondTraits::canInitializeWithMemset; |
| static const bool canMoveWithMemcpy = FirstTraits::canMoveWithMemcpy && SecondTraits::canMoveWithMemcpy; |
| static const bool canCopyWithMemcpy = FirstTraits::canCopyWithMemcpy && SecondTraits::canCopyWithMemcpy; |
| static const bool canFillWithMemset = false; |
| static const bool canCompareWithMemcmp = FirstTraits::canCompareWithMemcmp && SecondTraits::canCompareWithMemcmp; |
| template <typename U = void> |
| struct NeedsTracingLazily { |
| static const bool value = ShouldBeTraced<FirstTraits>::value || ShouldBeTraced<SecondTraits>::value; |
| }; |
| static const WeakHandlingFlag weakHandlingFlag = NoWeakHandlingInCollections; // We don't support weak handling in vectors. |
| }; |
| |
| } // namespace WTF |
| |
| #define WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(ClassName) \ |
| namespace WTF { \ |
| COMPILE_ASSERT(!IsTriviallyDefaultConstructible<ClassName>::value || !IsTriviallyCopyAssignable<ClassName>::value, macro_not_needed); \ |
| template<> \ |
| struct VectorTraits<ClassName> : SimpleClassVectorTraits<ClassName> { }; \ |
| } |
| |
| #define WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(ClassName) \ |
| namespace WTF { \ |
| COMPILE_ASSERT(!WTF::IsTriviallyDefaultConstructible<ClassName>::value || !IsTriviallyCopyAssignable<ClassName>::value, macro_not_needed); \ |
| template<> \ |
| struct VectorTraits<ClassName> : VectorTraitsBase<ClassName> \ |
| { \ |
| static const bool canInitializeWithMemset = true; \ |
| static const bool canMoveWithMemcpy = true; \ |
| }; \ |
| } |
| |
| #define WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(ClassName) \ |
| namespace WTF { \ |
| COMPILE_ASSERT(!WTF::IsTriviallyDefaultConstructible<ClassName>::value, macro_not_needed); \ |
| template<> \ |
| struct VectorTraits<ClassName> : VectorTraitsBase<ClassName> \ |
| { \ |
| static const bool canInitializeWithMemset = true; \ |
| }; \ |
| } |
| |
| using WTF::VectorTraits; |
| using WTF::SimpleClassVectorTraits; |
| |
| #endif // WTF_VectorTraits_h |