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1 // Copyright 2015 The Chromium Authors. All rights reserved. | 1 // Copyright 2015 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef BASE_MEMORY_PTR_UTIL_H_ | 5 #ifndef BASE_MEMORY_PTR_UTIL_H_ |
6 #define BASE_MEMORY_PTR_UTIL_H_ | 6 #define BASE_MEMORY_PTR_UTIL_H_ |
7 | 7 |
8 #include <memory> | 8 #include <memory> |
9 | 9 |
10 // A function to convert T* into scoped_ptr<T> | |
11 // Doing e.g. make_scoped_ptr(new FooBarBaz<type>(arg)) is a shorter notation | |
12 // for scoped_ptr<FooBarBaz<type>>(new FooBarBaz<type>(arg)) | |
13 // | |
14 // Why doesn't this just return a scoped_ptr? | |
15 // | |
16 // make_scoped_ptr is currently being migrated out of scoped_ptr.h, so we can | |
17 // globally rename make_scoped_ptr to WrapUnique without breaking the build. | |
18 // Doing so without breaking intermediate builds involves several steps: | |
19 // | |
20 // 1. Move make_scoped_ptr into ptr_util.h and include ptr_util.h from | |
21 // scoped_ptr.h. | |
22 // 2. Add an #include for ptr_util.h to every file that references | |
23 // make_scoped_ptr. | |
24 // 3. Remove ptr_util.h include from scoped_ptr.h. | |
25 // 4. Global rewrite everything. | |
26 // | |
27 // Unfortunately, step 1 introduces an awkward cycle of dependencies between | |
28 // ptr_util.h and scoped_ptr.h To break that cycle, we exploit the fact that | |
29 // scoped_ptr is really just a type alias for std::unique_ptr. | |
30 template <typename T> | |
31 std::unique_ptr<T> make_scoped_ptr(T* ptr) { | |
32 return std::unique_ptr<T>(ptr); | |
33 } | |
34 | |
35 namespace base { | 10 namespace base { |
36 | 11 |
37 // Helper to transfer ownership of a raw pointer to a std::unique_ptr<T>. | 12 // Helper to transfer ownership of a raw pointer to a std::unique_ptr<T>. |
38 // Note that std::unique_ptr<T> has very different semantics from | 13 // Note that std::unique_ptr<T> has very different semantics from |
39 // std::unique_ptr<T[]>: do not use this helper for array allocations. | 14 // std::unique_ptr<T[]>: do not use this helper for array allocations. |
40 template <typename T> | 15 template <typename T> |
41 std::unique_ptr<T> WrapUnique(T* ptr) { | 16 std::unique_ptr<T> WrapUnique(T* ptr) { |
42 return std::unique_ptr<T>(ptr); | 17 return std::unique_ptr<T>(ptr); |
43 } | 18 } |
44 | 19 |
45 } // namespace base | 20 } // namespace base |
46 | 21 |
47 #endif // BASE_MEMORY_PTR_UTIL_H_ | 22 #endif // BASE_MEMORY_PTR_UTIL_H_ |
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