gecko-dev/security/pkix/lib/ScopedPtr.h

84 строки
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This code is made available to you under your choice of the following sets
* of licensing terms:
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* Copyright 2013 Mozilla Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef mozilla_pkix_ScopedPtr_h
#define mozilla_pkix_ScopedPtr_h
namespace mozilla { namespace pkix {
// A subset polyfill of std::unique_ptr that does not support move construction
// or move assignment. This is used instead of std::unique_ptr because some
// important toolchains still don't provide std::unique_ptr, including in
// particular Android NDK projects with APP_STL=stlport_static or
// ALL_STL=stlport_shared.
template <typename T, void (&Destroyer)(T*)>
class ScopedPtr final
{
public:
explicit ScopedPtr(T* value = nullptr) : mValue(value) { }
ScopedPtr(const ScopedPtr&) = delete;
~ScopedPtr()
{
if (mValue) {
Destroyer(mValue);
}
}
void operator=(const ScopedPtr&) = delete;
T& operator*() const { return *mValue; }
T* operator->() const { return mValue; }
explicit operator bool() const { return mValue; }
T* get() const { return mValue; }
T* release()
{
T* result = mValue;
mValue = nullptr;
return result;
}
void reset(T* newValue = nullptr)
{
// The C++ standard requires std::unique_ptr to destroy the old value
// pointed to by mValue, if any, *after* assigning the new value to mValue.
T* oldValue = mValue;
mValue = newValue;
if (oldValue) {
Destroyer(oldValue);
}
}
private:
T* mValue;
};
} } // namespace mozilla::pkix
#endif // mozilla_pkix_ScopedPtr_h