Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This code is made available to you under your choice of the following sets
       4             :  * of licensing terms:
       5             :  */
       6             : /* This Source Code Form is subject to the terms of the Mozilla Public
       7             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       8             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
       9             :  */
      10             : /* Copyright 2013 Mozilla Contributors
      11             :  *
      12             :  * Licensed under the Apache License, Version 2.0 (the "License");
      13             :  * you may not use this file except in compliance with the License.
      14             :  * You may obtain a copy of the License at
      15             :  *
      16             :  *     http://www.apache.org/licenses/LICENSE-2.0
      17             :  *
      18             :  * Unless required by applicable law or agreed to in writing, software
      19             :  * distributed under the License is distributed on an "AS IS" BASIS,
      20             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      21             :  * See the License for the specific language governing permissions and
      22             :  * limitations under the License.
      23             :  */
      24             : 
      25             : #ifndef mozilla_pkix_ScopedPtr_h
      26             : #define mozilla_pkix_ScopedPtr_h
      27             : 
      28             : namespace mozilla { namespace pkix {
      29             : 
      30             : // A subset polyfill of std::unique_ptr that does not support move construction
      31             : // or move assignment. This is used instead of std::unique_ptr because some
      32             : // important toolchains still don't provide std::unique_ptr, including in
      33             : // particular Android NDK projects with APP_STL=stlport_static or
      34             : // ALL_STL=stlport_shared.
      35             : template <typename T, void (&Destroyer)(T*)>
      36             : class ScopedPtr final
      37             : {
      38             : public:
      39           0 :   explicit ScopedPtr(T* value = nullptr) : mValue(value) { }
      40             : 
      41             :   ScopedPtr(const ScopedPtr&) = delete;
      42             : 
      43           0 :   ~ScopedPtr()
      44             :   {
      45           0 :     if (mValue) {
      46           0 :       Destroyer(mValue);
      47             :     }
      48           0 :   }
      49             : 
      50             :   void operator=(const ScopedPtr&) = delete;
      51             : 
      52             :   T& operator*() const { return *mValue; }
      53             :   T* operator->() const { return mValue; }
      54             : 
      55           0 :   explicit operator bool() const { return mValue; }
      56             : 
      57           0 :   T* get() const { return mValue; }
      58             : 
      59             :   T* release()
      60             :   {
      61             :     T* result = mValue;
      62             :     mValue = nullptr;
      63             :     return result;
      64             :   }
      65             : 
      66             :   void reset(T* newValue = nullptr)
      67             :   {
      68             :     // The C++ standard requires std::unique_ptr to destroy the old value
      69             :     // pointed to by mValue, if any, *after* assigning the new value to mValue.
      70             :     T* oldValue = mValue;
      71             :     mValue = newValue;
      72             :     if (oldValue) {
      73             :       Destroyer(oldValue);
      74             :     }
      75             :   }
      76             : 
      77             : private:
      78             :   T* mValue;
      79             : };
      80             : 
      81             : } } // namespace mozilla::pkix
      82             : 
      83             : #endif // mozilla_pkix_ScopedPtr_h