cygprofile: increase timeouts to allow showing web contents
[chromium-blink-merge.git] / third_party / cld / base / scoped_ptr.h
blobd19ff39109c5aebc21d312162e4814c20bb952fd
1 // Copyright (c) 2006-2009 The Chromium 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.
5 #ifndef BASE_SCOPED_PTR_H__
6 #define BASE_SCOPED_PTR_H__
8 // This is an implementation designed to match the anticipated future TR2
9 // implementation of the scoped_ptr class, and its closely-related brethren,
10 // scoped_array, scoped_ptr_malloc, and make_scoped_ptr.
12 // See http://wiki/Main/ScopedPointerInterface for the spec that drove this
13 // file.
15 #include <assert.h>
16 #include <stdlib.h>
17 #include <cstddef>
19 #ifdef OS_EMBEDDED_QNX
20 // NOTE(akirmse):
21 // The C++ standard says that <stdlib.h> declares both ::foo and std::foo
22 // But this isn't done in QNX version 6.3.2 200709062316.
23 using std::free;
24 using std::malloc;
25 using std::realloc;
26 #endif
28 template <class C> class scoped_ptr;
29 template <class C, class Free> class scoped_ptr_malloc;
30 template <class C> class scoped_array;
32 template <class C>
33 scoped_ptr<C> make_scoped_ptr(C *);
35 // A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
36 // automatically deletes the pointer it holds (if any).
37 // That is, scoped_ptr<T> owns the T object that it points to.
38 // Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
39 // Also like T*, scoped_ptr<T> is thread-compatible, and once you
40 // dereference it, you get the threadsafety guarantees of T.
42 // The size of a scoped_ptr is small:
43 // sizeof(scoped_ptr<C>) == sizeof(C*)
44 template <class C>
45 class scoped_ptr {
46 public:
48 // The element type
49 typedef C element_type;
51 // Constructor. Defaults to intializing with NULL.
52 // There is no way to create an uninitialized scoped_ptr.
53 // The input parameter must be allocated with new.
54 explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
56 // Destructor. If there is a C object, delete it.
57 // We don't need to test ptr_ == NULL because C++ does that for us.
58 ~scoped_ptr() {
59 enum { type_must_be_complete = sizeof(C) };
60 delete ptr_;
63 // Reset. Deletes the current owned object, if any.
64 // Then takes ownership of a new object, if given.
65 // this->reset(this->get()) works.
66 void reset(C* p = NULL) {
67 if (p != ptr_) {
68 enum { type_must_be_complete = sizeof(C) };
69 delete ptr_;
70 ptr_ = p;
74 // Accessors to get the owned object.
75 // operator* and operator-> will assert() if there is no current object.
76 C& operator*() const {
77 assert(ptr_ != NULL);
78 return *ptr_;
80 C* operator->() const {
81 assert(ptr_ != NULL);
82 return ptr_;
84 C* get() const { return ptr_; }
86 // Comparison operators.
87 // These return whether a scoped_ptr and a raw pointer refer to
88 // the same object, not just to two different but equal objects.
89 bool operator==(const C* p) const { return ptr_ == p; }
90 bool operator!=(const C* p) const { return ptr_ != p; }
92 // Swap two scoped pointers.
93 void swap(scoped_ptr& p2) {
94 C* tmp = ptr_;
95 ptr_ = p2.ptr_;
96 p2.ptr_ = tmp;
99 // Release a pointer.
100 // The return value is the current pointer held by this object.
101 // If this object holds a NULL pointer, the return value is NULL.
102 // After this operation, this object will hold a NULL pointer,
103 // and will not own the object any more.
104 C* release() {
105 C* retVal = ptr_;
106 ptr_ = NULL;
107 return retVal;
110 private:
111 C* ptr_;
113 // google3 friend class that can access copy ctor (although if it actually
114 // calls a copy ctor, there will be a problem) see below
115 friend scoped_ptr<C> make_scoped_ptr<C>(C *p);
117 // Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't
118 // make sense, and if C2 == C, it still doesn't make sense because you should
119 // never have the same object owned by two different scoped_ptrs.
120 template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
121 template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
123 // Disallow evil constructors
124 scoped_ptr(const scoped_ptr&);
125 void operator=(const scoped_ptr&);
128 // Free functions
129 template <class C>
130 inline void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
131 p1.swap(p2);
134 template <class C>
135 inline bool operator==(const C* p1, const scoped_ptr<C>& p2) {
136 return p1 == p2.get();
139 template <class C>
140 inline bool operator==(const C* p1, const scoped_ptr<const C>& p2) {
141 return p1 == p2.get();
144 template <class C>
145 inline bool operator!=(const C* p1, const scoped_ptr<C>& p2) {
146 return p1 != p2.get();
149 template <class C>
150 inline bool operator!=(const C* p1, const scoped_ptr<const C>& p2) {
151 return p1 != p2.get();
154 template <class C>
155 scoped_ptr<C> make_scoped_ptr(C *p) {
156 // This does nothing but to return a scoped_ptr of the type that the passed
157 // pointer is of. (This eliminates the need to specify the name of T when
158 // making a scoped_ptr that is used anonymously/temporarily.) From an
159 // access control point of view, we construct an unnamed scoped_ptr here
160 // which we return and thus copy-construct. Hence, we need to have access
161 // to scoped_ptr::scoped_ptr(scoped_ptr const &). However, it is guaranteed
162 // that we never actually call the copy constructor, which is a good thing
163 // as we would call the temporary's object destructor (and thus delete p)
164 // if we actually did copy some object, here.
165 return scoped_ptr<C>(p);
168 // scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
169 // with new [] and the destructor deletes objects with delete [].
171 // As with scoped_ptr<C>, a scoped_array<C> either points to an object
172 // or is NULL. A scoped_array<C> owns the object that it points to.
173 // scoped_array<T> is thread-compatible, and once you index into it,
174 // the returned objects have only the threadsafety guarantees of T.
176 // Size: sizeof(scoped_array<C>) == sizeof(C*)
177 template <class C>
178 class scoped_array {
179 public:
181 // The element type
182 typedef C element_type;
184 // Constructor. Defaults to intializing with NULL.
185 // There is no way to create an uninitialized scoped_array.
186 // The input parameter must be allocated with new [].
187 explicit scoped_array(C* p = NULL) : array_(p) { }
189 // Destructor. If there is a C object, delete it.
190 // We don't need to test ptr_ == NULL because C++ does that for us.
191 ~scoped_array() {
192 enum { type_must_be_complete = sizeof(C) };
193 delete[] array_;
196 // Reset. Deletes the current owned object, if any.
197 // Then takes ownership of a new object, if given.
198 // this->reset(this->get()) works.
199 void reset(C* p = NULL) {
200 if (p != array_) {
201 enum { type_must_be_complete = sizeof(C) };
202 delete[] array_;
203 array_ = p;
207 // Get one element of the current object.
208 // Will assert() if there is no current object, or index i is negative.
209 C& operator[](std::ptrdiff_t i) const {
210 assert(i >= 0);
211 assert(array_ != NULL);
212 return array_[i];
215 // Get a pointer to the zeroth element of the current object.
216 // If there is no current object, return NULL.
217 C* get() const {
218 return array_;
221 // Comparison operators.
222 // These return whether a scoped_array and a raw pointer refer to
223 // the same array, not just to two different but equal arrays.
224 bool operator==(const C* p) const { return array_ == p; }
225 bool operator!=(const C* p) const { return array_ != p; }
227 // Swap two scoped arrays.
228 void swap(scoped_array& p2) {
229 C* tmp = array_;
230 array_ = p2.array_;
231 p2.array_ = tmp;
234 // Release an array.
235 // The return value is the current pointer held by this object.
236 // If this object holds a NULL pointer, the return value is NULL.
237 // After this operation, this object will hold a NULL pointer,
238 // and will not own the object any more.
239 C* release() {
240 C* retVal = array_;
241 array_ = NULL;
242 return retVal;
245 private:
246 C* array_;
248 // Forbid comparison of different scoped_array types.
249 template <class C2> bool operator==(scoped_array<C2> const& p2) const;
250 template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
252 // Disallow evil constructors
253 scoped_array(const scoped_array&);
254 void operator=(const scoped_array&);
257 // Free functions
258 template <class C>
259 inline void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
260 p1.swap(p2);
263 template <class C>
264 inline bool operator==(const C* p1, const scoped_array<C>& p2) {
265 return p1 == p2.get();
268 template <class C>
269 inline bool operator==(const C* p1, const scoped_array<const C>& p2) {
270 return p1 == p2.get();
273 template <class C>
274 inline bool operator!=(const C* p1, const scoped_array<C>& p2) {
275 return p1 != p2.get();
278 template <class C>
279 inline bool operator!=(const C* p1, const scoped_array<const C>& p2) {
280 return p1 != p2.get();
283 // This class wraps the c library function free() in a class that can be
284 // passed as a template argument to scoped_ptr_malloc below.
285 class ScopedPtrMallocFree {
286 public:
287 inline void operator()(void* x) const {
288 free(x);
292 // scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
293 // second template argument, the functor used to free the object.
295 template<class C, class FreeProc = ScopedPtrMallocFree>
296 class scoped_ptr_malloc {
297 public:
299 // The element type
300 typedef C element_type;
302 // Construction with no arguments sets ptr_ to NULL.
303 // There is no way to create an uninitialized scoped_ptr.
304 // The input parameter must be allocated with an allocator that matches the
305 // Free functor. For the default Free functor, this is malloc, calloc, or
306 // realloc.
307 explicit scoped_ptr_malloc(): ptr_(NULL) { }
309 // Construct with a C*, and provides an error with a D*.
310 template<class must_be_C>
311 explicit scoped_ptr_malloc(must_be_C* p): ptr_(p) { }
313 // Construct with a void*, such as you get from malloc.
314 explicit scoped_ptr_malloc(void *p): ptr_(static_cast<C*>(p)) { }
316 // Destructor. If there is a C object, call the Free functor.
317 ~scoped_ptr_malloc() {
318 free_(ptr_);
321 // Reset. Calls the Free functor on the current owned object, if any.
322 // Then takes ownership of a new object, if given.
323 // this->reset(this->get()) works.
324 void reset(C* p = NULL) {
325 if (ptr_ != p) {
326 free_(ptr_);
327 ptr_ = p;
331 // Reallocates the existing pointer, and returns 'true' if
332 // the reallcation is succesfull. If the reallocation failed, then
333 // the pointer remains in its previous state.
335 // Note: this calls realloc() directly, even if an alternate 'free'
336 // functor is provided in the template instantiation.
337 bool try_realloc(size_t new_size) {
338 C* new_ptr = static_cast<C*>(realloc(ptr_, new_size));
339 if (new_ptr == NULL) {
340 return false;
342 ptr_ = new_ptr;
343 return true;
346 // Get the current object.
347 // operator* and operator-> will cause an assert() failure if there is
348 // no current object.
349 C& operator*() const {
350 assert(ptr_ != NULL);
351 return *ptr_;
354 C* operator->() const {
355 assert(ptr_ != NULL);
356 return ptr_;
359 C* get() const {
360 return ptr_;
363 // Comparison operators.
364 // These return whether a scoped_ptr_malloc and a plain pointer refer
365 // to the same object, not just to two different but equal objects.
366 // For compatibility with the boost-derived implementation, these
367 // take non-const arguments.
368 bool operator==(C* p) const {
369 return ptr_ == p;
372 bool operator!=(C* p) const {
373 return ptr_ != p;
376 // Swap two scoped pointers.
377 void swap(scoped_ptr_malloc & b) {
378 C* tmp = b.ptr_;
379 b.ptr_ = ptr_;
380 ptr_ = tmp;
383 // Release a pointer.
384 // The return value is the current pointer held by this object.
385 // If this object holds a NULL pointer, the return value is NULL.
386 // After this operation, this object will hold a NULL pointer,
387 // and will not own the object any more.
388 C* release() {
389 C* tmp = ptr_;
390 ptr_ = NULL;
391 return tmp;
394 private:
395 C* ptr_;
397 // no reason to use these: each scoped_ptr_malloc should have its own object
398 template <class C2, class GP>
399 bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
400 template <class C2, class GP>
401 bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
403 static FreeProc const free_;
405 // Disallow evil constructors
406 scoped_ptr_malloc(const scoped_ptr_malloc&);
407 void operator=(const scoped_ptr_malloc&);
410 template<class C, class FP>
411 FP const scoped_ptr_malloc<C, FP>::free_ = FP();
413 template<class C, class FP> inline
414 void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
415 a.swap(b);
418 template<class C, class FP> inline
419 bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
420 return p == b.get();
423 template<class C, class FP> inline
424 bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
425 return p != b.get();
428 #endif // BASE_SCOPED_PTR_H__