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/*
* Copyright (C) 2014-2021 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
// Adapted from
#ifndef mozilla_DarwinObjectPtr_h
#define mozilla_DarwinObjectPtr_h
#include <os/object.h>
#include <utility>
#include "mozilla/Attributes.h"
// Because ARC enablement is a compile-time choice, and we compile this header
// both ways, we need a separate copy of our code when ARC is enabled.
#if __has_feature(objc_arc)
# define AdoptDarwinObject AdoptDarwinObjectArc
# define RetainDarwinObject RetainDarwinObjectArc
# define ReleaseDarwinObject ReleaseDarwinObjectArc
#endif
namespace mozilla {
template <typename>
class DarwinObjectPtr;
template <typename T>
[[nodiscard]] DarwinObjectPtr<T> AdoptDarwinObject(T);
template <typename T>
static inline void RetainDarwinObject(T aPtr) {
#if !__has_feature(objc_arc)
os_retain(aPtr);
#endif
}
template <typename T>
static inline void ReleaseDarwinObject(T aPtr) {
#if !__has_feature(objc_arc)
os_release(aPtr);
#endif
}
template <typename T>
class DarwinObjectPtr {
public:
DarwinObjectPtr() : mPtr(nullptr) {}
~DarwinObjectPtr() {
if (mPtr) {
ReleaseDarwinObject(mPtr);
}
}
T get() const { return mPtr; }
explicit operator bool() const { return mPtr; }
bool operator!() const { return !mPtr; }
DarwinObjectPtr(const DarwinObjectPtr& aOther) : mPtr(aOther.mPtr) {
if (mPtr) {
RetainDarwinObject(mPtr);
}
}
DarwinObjectPtr(DarwinObjectPtr&& aOther) : mPtr(std::move(aOther.mPtr)) {
aOther.mPtr = nullptr;
}
MOZ_IMPLICIT DarwinObjectPtr(T aPtr) : mPtr(std::move(aPtr)) {
if (mPtr) {
RetainDarwinObject(mPtr);
}
}
DarwinObjectPtr& operator=(const DarwinObjectPtr& aOther) {
DarwinObjectPtr ptr = aOther;
swap(ptr);
return *this;
}
DarwinObjectPtr& operator=(DarwinObjectPtr&& aOther) {
DarwinObjectPtr ptr = std::move(aOther);
swap(ptr);
return *this;
}
DarwinObjectPtr& operator=(std::nullptr_t) {
if (mPtr) {
ReleaseDarwinObject(mPtr);
}
mPtr = nullptr;
return *this;
}
DarwinObjectPtr& operator=(T aOther) {
DarwinObjectPtr ptr = std::move(aOther);
swap(ptr);
return *this;
}
void swap(DarwinObjectPtr& aOther) { std::swap(mPtr, aOther.mPtr); }
[[nodiscard]] T forget() { return std::exchange(mPtr, nullptr); }
friend DarwinObjectPtr AdoptDarwinObject<T>(T);
private:
struct AdoptDarwinObjectTag {};
DarwinObjectPtr(AdoptDarwinObjectTag, T aPtr) : mPtr(std::move(aPtr)) {}
T mPtr;
};
template <typename T>
inline DarwinObjectPtr<T> AdoptDarwinObject(T aPtr) {
return DarwinObjectPtr<T>{typename DarwinObjectPtr<T>::AdoptDarwinObjectTag{},
std::move(aPtr)};
}
} // namespace mozilla
#endif