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1 : // Protocol Buffers - Google's data interchange format
2 : // Copyright 2008 Google Inc. All rights reserved.
3 : // https://developers.google.com/protocol-buffers/
4 : //
5 : // Redistribution and use in source and binary forms, with or without
6 : // modification, are permitted provided that the following conditions are
7 : // met:
8 : //
9 : // * Redistributions of source code must retain the above copyright
10 : // notice, this list of conditions and the following disclaimer.
11 : // * Redistributions in binary form must reproduce the above
12 : // copyright notice, this list of conditions and the following disclaimer
13 : // in the documentation and/or other materials provided with the
14 : // distribution.
15 : // * Neither the name of Google Inc. nor the names of its
16 : // contributors may be used to endorse or promote products derived from
17 : // this software without specific prior written permission.
18 : //
19 : // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 : // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 : // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 : // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 : // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 : // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 : // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 : // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 : // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 : // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 : // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 :
31 : #ifndef GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_
32 : #define GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_
33 :
34 : #include <google/protobuf/stubs/port.h>
35 :
36 : namespace google {
37 : namespace protobuf {
38 :
39 : // ===================================================================
40 : // from google3/base/scoped_ptr.h
41 :
42 : namespace internal {
43 :
44 : // This is an implementation designed to match the anticipated future TR2
45 : // implementation of the scoped_ptr class, and its closely-related brethren,
46 : // scoped_array, scoped_ptr_malloc, and make_scoped_ptr.
47 :
48 : template <class C> class scoped_ptr;
49 : template <class C> class scoped_array;
50 :
51 : // A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
52 : // automatically deletes the pointer it holds (if any).
53 : // That is, scoped_ptr<T> owns the T object that it points to.
54 : // Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
55 : //
56 : // The size of a scoped_ptr is small:
57 : // sizeof(scoped_ptr<C>) == sizeof(C*)
58 : template <class C>
59 : class scoped_ptr {
60 : public:
61 :
62 : // The element type
63 : typedef C element_type;
64 :
65 : // Constructor. Defaults to initializing with NULL.
66 : // There is no way to create an uninitialized scoped_ptr.
67 : // The input parameter must be allocated with new.
68 5246 : explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
69 :
70 : // Destructor. If there is a C object, delete it.
71 : // We don't need to test ptr_ == NULL because C++ does that for us.
72 1294 : ~scoped_ptr() {
73 : enum { type_must_be_complete = sizeof(C) };
74 5304 : delete ptr_;
75 1294 : }
76 :
77 : // Reset. Deletes the current owned object, if any.
78 : // Then takes ownership of a new object, if given.
79 : // this->reset(this->get()) works.
80 768 : void reset(C* p = NULL) {
81 4464 : if (p != ptr_) {
82 : enum { type_must_be_complete = sizeof(C) };
83 4456 : delete ptr_;
84 4456 : ptr_ = p;
85 : }
86 768 : }
87 :
88 : // Accessors to get the owned object.
89 : // operator* and operator-> will assert() if there is no current object.
90 : C& operator*() const {
91 : assert(ptr_ != NULL);
92 34795 : return *ptr_;
93 : }
94 : C* operator->() const {
95 : assert(ptr_ != NULL);
96 13578 : return ptr_;
97 : }
98 1252 : C* get() const { return ptr_; }
99 :
100 : // Comparison operators.
101 : // These return whether two scoped_ptr refer to the same object, not just to
102 : // two different but equal objects.
103 : bool operator==(C* p) const { return ptr_ == p; }
104 0 : bool operator!=(C* p) const { return ptr_ != p; }
105 :
106 : // Swap two scoped pointers.
107 : void swap(scoped_ptr& p2) {
108 : C* tmp = ptr_;
109 : ptr_ = p2.ptr_;
110 : p2.ptr_ = tmp;
111 : }
112 :
113 : // Release a pointer.
114 : // The return value is the current pointer held by this object.
115 : // If this object holds a NULL pointer, the return value is NULL.
116 : // After this operation, this object will hold a NULL pointer,
117 : // and will not own the object any more.
118 : C* release() {
119 31 : C* retVal = ptr_;
120 31 : ptr_ = NULL;
121 : return retVal;
122 : }
123 :
124 : private:
125 : C* ptr_;
126 :
127 : // Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't
128 : // make sense, and if C2 == C, it still doesn't make sense because you should
129 : // never have the same object owned by two different scoped_ptrs.
130 : template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
131 : template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
132 :
133 : // Disallow evil constructors
134 : scoped_ptr(const scoped_ptr&);
135 : void operator=(const scoped_ptr&);
136 : };
137 :
138 : // scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
139 : // with new [] and the destructor deletes objects with delete [].
140 : //
141 : // As with scoped_ptr<C>, a scoped_array<C> either points to an object
142 : // or is NULL. A scoped_array<C> owns the object that it points to.
143 : //
144 : // Size: sizeof(scoped_array<C>) == sizeof(C*)
145 : template <class C>
146 : class scoped_array {
147 : public:
148 :
149 : // The element type
150 : typedef C element_type;
151 :
152 : // Constructor. Defaults to initializing with NULL.
153 : // There is no way to create an uninitialized scoped_array.
154 : // The input parameter must be allocated with new [].
155 14919 : explicit scoped_array(C* p = NULL) : array_(p) { }
156 :
157 : // Destructor. If there is a C object, delete it.
158 : // We don't need to test ptr_ == NULL because C++ does that for us.
159 1852 : ~scoped_array() {
160 : enum { type_must_be_complete = sizeof(C) };
161 14795 : delete[] array_;
162 1852 : }
163 :
164 : // Reset. Deletes the current owned object, if any.
165 : // Then takes ownership of a new object, if given.
166 : // this->reset(this->get()) works.
167 : void reset(C* p = NULL) {
168 185 : if (p != array_) {
169 : enum { type_must_be_complete = sizeof(C) };
170 185 : delete[] array_;
171 185 : array_ = p;
172 : }
173 : }
174 :
175 : // Get one element of the current object.
176 : // Will assert() if there is no current object, or index i is negative.
177 : C& operator[](std::ptrdiff_t i) const {
178 : assert(i >= 0);
179 : assert(array_ != NULL);
180 49511 : return array_[i];
181 : }
182 :
183 : // Get a pointer to the zeroth element of the current object.
184 : // If there is no current object, return NULL.
185 : C* get() const {
186 602 : return array_;
187 : }
188 :
189 : // Comparison operators.
190 : // These return whether two scoped_array refer to the same object, not just to
191 : // two different but equal objects.
192 18 : bool operator==(C* p) const { return array_ == p; }
193 : bool operator!=(C* p) const { return array_ != p; }
194 :
195 : // Swap two scoped arrays.
196 : void swap(scoped_array& p2) {
197 : C* tmp = array_;
198 : array_ = p2.array_;
199 : p2.array_ = tmp;
200 : }
201 :
202 : // Release an array.
203 : // The return value is the current pointer held by this object.
204 : // If this object holds a NULL pointer, the return value is NULL.
205 : // After this operation, this object will hold a NULL pointer,
206 : // and will not own the object any more.
207 : C* release() {
208 : C* retVal = array_;
209 : array_ = NULL;
210 : return retVal;
211 : }
212 :
213 : private:
214 : C* array_;
215 :
216 : // Forbid comparison of different scoped_array types.
217 : template <class C2> bool operator==(scoped_array<C2> const& p2) const;
218 : template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
219 :
220 : // Disallow evil constructors
221 : scoped_array(const scoped_array&);
222 : void operator=(const scoped_array&);
223 : };
224 :
225 : } // namespace internal
226 :
227 : // We made these internal so that they would show up as such in the docs,
228 : // but we don't want to stick "internal::" in front of them everywhere.
229 : using internal::scoped_ptr;
230 : using internal::scoped_array;
231 :
232 :
233 : } // namespace protobuf
234 : } // namespace google
235 :
236 : #endif // GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_
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