Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(1)

Side by Side Diff: src/base/smart-pointers.h

Issue 2175233003: Replace SmartPointer<T> with unique_ptr<T> (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@smart-array
Patch Set: Created 4 years, 4 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
OLDNEW
(Empty)
1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef V8_BASE_SMART_POINTERS_H_
6 #define V8_BASE_SMART_POINTERS_H_
7
8 #include "src/base/logging.h"
9
10 namespace v8 {
11 namespace base {
12
13 template <typename Deallocator, typename T>
14 class SmartPointerBase {
15 public:
16 // Default constructor. Constructs an empty scoped pointer.
17 SmartPointerBase() : p_(NULL) {}
18
19 // Constructs a scoped pointer from a plain one.
20 explicit SmartPointerBase(T* ptr) : p_(ptr) {}
21
22 // Copy constructor removes the pointer from the original to avoid double
23 // freeing.
24 SmartPointerBase(const SmartPointerBase<Deallocator, T>& rhs) : p_(rhs.p_) {
25 const_cast<SmartPointerBase<Deallocator, T>&>(rhs).p_ = NULL;
26 }
27
28 T* operator->() const { return p_; }
29
30 T& operator*() const { return *p_; }
31
32 T* get() const { return p_; }
33
34 // You can use [n] to index as if it was a plain pointer.
35 T& operator[](size_t i) { return p_[i]; }
36
37 // You can use [n] to index as if it was a plain pointer.
38 const T& operator[](size_t i) const { return p_[i]; }
39
40 // We don't have implicit conversion to a T* since that hinders migration:
41 // You would not be able to change a method from returning a T* to
42 // returning an SmartArrayPointer<T> and then get errors wherever it is used.
43
44
45 // If you want to take out the plain pointer and don't want it automatically
46 // deleted then call Detach(). Afterwards, the smart pointer is empty
47 // (NULL).
48 T* Detach() {
49 T* temp = p_;
50 p_ = NULL;
51 return temp;
52 }
53
54 void Reset(T* new_value) {
55 DCHECK(p_ == NULL || p_ != new_value);
56 if (p_) Deallocator::Delete(p_);
57 p_ = new_value;
58 }
59
60 // Assignment requires an empty (NULL) SmartArrayPointer as the receiver. Like
61 // the copy constructor it removes the pointer in the original to avoid
62 // double freeing.
63 SmartPointerBase<Deallocator, T>& operator=(
64 const SmartPointerBase<Deallocator, T>& rhs) {
65 DCHECK(is_empty());
66 T* tmp = rhs.p_; // swap to handle self-assignment
67 const_cast<SmartPointerBase<Deallocator, T>&>(rhs).p_ = NULL;
68 p_ = tmp;
69 return *this;
70 }
71
72 bool is_empty() const { return p_ == NULL; }
73
74 protected:
75 // When the destructor of the scoped pointer is executed the plain pointer
76 // is deleted using DeleteArray. This implies that you must allocate with
77 // NewArray.
78 ~SmartPointerBase() {
79 if (p_) Deallocator::Delete(p_);
80 }
81
82 private:
83 T* p_;
84 };
85
86 template <typename T>
87 struct ObjectDeallocator {
88 static void Delete(T* object) { delete object; }
89 };
90
91 template <typename T>
92 class SmartPointer : public SmartPointerBase<ObjectDeallocator<T>, T> {
93 public:
94 SmartPointer() {}
95 explicit SmartPointer(T* ptr)
96 : SmartPointerBase<ObjectDeallocator<T>, T>(ptr) {}
97 SmartPointer(const SmartPointer<T>& rhs)
98 : SmartPointerBase<ObjectDeallocator<T>, T>(rhs) {}
99 };
100
101 } // namespace base
102 } // namespace v8
103
104 #endif // V8_SMART_POINTERS_H_
OLDNEW

Powered by Google App Engine
This is Rietveld 408576698