ladybird/AK/OwnPtr.h
Andreas Kling 79fa9765ca Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T>
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace!
This was a slightly tedious refactoring that took a long time, so it's
not unlikely that some bugs crept in.

Nevertheless, it does pass basic functionality testing, and it's just
real nice to finally see the same pattern in all contexts. :^)
2021-11-08 01:10:53 +01:00

245 lines
5.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Error.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/RefCounted.h>
#define OWNPTR_SCRUB_BYTE 0xf0
namespace AK {
template<typename T>
class OwnPtr {
public:
OwnPtr() = default;
OwnPtr(decltype(nullptr))
: m_ptr(nullptr)
{
}
OwnPtr(OwnPtr&& other)
: m_ptr(other.leak_ptr())
{
}
template<typename U>
OwnPtr(NonnullOwnPtr<U>&& other)
: m_ptr(other.leak_ptr())
{
}
template<typename U>
OwnPtr(OwnPtr<U>&& other)
: m_ptr(other.leak_ptr())
{
}
~OwnPtr()
{
clear();
#ifdef SANITIZE_PTRS
m_ptr = (T*)(explode_byte(OWNPTR_SCRUB_BYTE));
#endif
}
OwnPtr(const OwnPtr&) = delete;
template<typename U>
OwnPtr(const OwnPtr<U>&) = delete;
OwnPtr& operator=(const OwnPtr&) = delete;
template<typename U>
OwnPtr& operator=(const OwnPtr<U>&) = delete;
template<typename U>
OwnPtr(const NonnullOwnPtr<U>&) = delete;
template<typename U>
OwnPtr& operator=(const NonnullOwnPtr<U>&) = delete;
template<typename U>
OwnPtr(const RefPtr<U>&) = delete;
template<typename U>
OwnPtr(const NonnullRefPtr<U>&) = delete;
template<typename U>
OwnPtr(const WeakPtr<U>&) = delete;
template<typename U>
OwnPtr& operator=(const RefPtr<U>&) = delete;
template<typename U>
OwnPtr& operator=(const NonnullRefPtr<U>&) = delete;
template<typename U>
OwnPtr& operator=(const WeakPtr<U>&) = delete;
OwnPtr& operator=(OwnPtr&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
return *this;
}
template<typename U>
OwnPtr& operator=(OwnPtr<U>&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
return *this;
}
template<typename U>
OwnPtr& operator=(NonnullOwnPtr<U>&& other)
{
OwnPtr ptr(move(other));
swap(ptr);
VERIFY(m_ptr);
return *this;
}
OwnPtr& operator=(T* ptr) = delete;
OwnPtr& operator=(std::nullptr_t)
{
clear();
return *this;
}
void clear()
{
delete m_ptr;
m_ptr = nullptr;
}
bool operator!() const { return !m_ptr; }
[[nodiscard]] T* leak_ptr()
{
T* leaked_ptr = m_ptr;
m_ptr = nullptr;
return leaked_ptr;
}
NonnullOwnPtr<T> release_nonnull()
{
VERIFY(m_ptr);
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, *leak_ptr());
}
template<typename U>
NonnullOwnPtr<U> release_nonnull()
{
VERIFY(m_ptr);
return NonnullOwnPtr<U>(NonnullOwnPtr<U>::Adopt, static_cast<U&>(*leak_ptr()));
}
T* ptr() { return m_ptr; }
const T* ptr() const { return m_ptr; }
T* operator->()
{
VERIFY(m_ptr);
return m_ptr;
}
const T* operator->() const
{
VERIFY(m_ptr);
return m_ptr;
}
T& operator*()
{
VERIFY(m_ptr);
return *m_ptr;
}
const T& operator*() const
{
VERIFY(m_ptr);
return *m_ptr;
}
operator const T*() const { return m_ptr; }
operator T*() { return m_ptr; }
operator bool() { return !!m_ptr; }
void swap(OwnPtr& other)
{
::swap(m_ptr, other.m_ptr);
}
template<typename U>
void swap(OwnPtr<U>& other)
{
::swap(m_ptr, other.m_ptr);
}
static OwnPtr lift(T* ptr)
{
return OwnPtr { ptr };
}
protected:
explicit OwnPtr(T* ptr)
: m_ptr(ptr)
{
static_assert(
requires { requires typename T::AllowOwnPtr()(); } || !requires { requires !typename T::AllowOwnPtr()(); declval<T>().ref(); declval<T>().unref(); }, "Use RefPtr<> for RefCounted types");
}
private:
T* m_ptr = nullptr;
};
template<typename T, typename U>
inline void swap(OwnPtr<T>& a, OwnPtr<U>& b)
{
a.swap(b);
}
template<typename T>
inline OwnPtr<T> adopt_own_if_nonnull(T* object)
{
if (object)
return OwnPtr<T>::lift(object);
return {};
}
template<typename T>
inline ErrorOr<NonnullOwnPtr<T>> adopt_nonnull_own_or_enomem(T* object)
{
auto result = adopt_own_if_nonnull(object);
if (!result)
return ENOMEM;
return result.release_nonnull();
}
template<typename T, class... Args>
requires(IsConstructible<T, Args...>) inline OwnPtr<T> try_make(Args&&... args)
{
return adopt_own_if_nonnull(new (nothrow) T(forward<Args>(args)...));
}
// FIXME: Remove once P0960R3 is available in Clang.
template<typename T, class... Args>
inline OwnPtr<T> try_make(Args&&... args)
{
return adopt_own_if_nonnull(new (nothrow) T { forward<Args>(args)... });
}
template<typename T>
struct Traits<OwnPtr<T>> : public GenericTraits<OwnPtr<T>> {
using PeekType = T*;
using ConstPeekType = const T*;
static unsigned hash(const OwnPtr<T>& p) { return ptr_hash(p.ptr()); }
static bool equals(const OwnPtr<T>& a, const OwnPtr<T>& b) { return a.ptr() == b.ptr(); }
};
}
using AK::adopt_nonnull_own_or_enomem;
using AK::adopt_own_if_nonnull;
using AK::OwnPtr;
using AK::try_make;