ladybird/AK/NonnullOwnPtr.h
2023-03-09 21:43:54 +01:00

220 lines
5.4 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Assertions.h>
#include <AK/Format.h>
#include <AK/RefCounted.h>
#include <AK/StdLibExtras.h>
#include <AK/Traits.h>
#include <AK/Types.h>
#define NONNULLOWNPTR_SCRUB_BYTE 0xf1
namespace AK {
template<typename T>
class WeakPtr;
template<typename T>
class [[nodiscard]] NonnullOwnPtr {
public:
using ElementType = T;
enum AdoptTag { Adopt };
NonnullOwnPtr(AdoptTag, T& ptr)
: m_ptr(&ptr)
{
static_assert(
requires { requires typename T::AllowOwnPtr()(); } || !requires { requires !typename T::AllowOwnPtr()(); declval<T>().ref(); declval<T>().unref(); },
"Use NonnullRefPtr<> for RefCounted types");
}
NonnullOwnPtr(NonnullOwnPtr&& other)
: m_ptr(other.leak_ptr())
{
VERIFY(m_ptr);
}
template<typename U>
NonnullOwnPtr(NonnullOwnPtr<U>&& other)
: m_ptr(other.leak_ptr())
{
VERIFY(m_ptr);
}
~NonnullOwnPtr()
{
clear();
#ifdef SANITIZE_PTRS
m_ptr = (T*)(explode_byte(NONNULLOWNPTR_SCRUB_BYTE));
#endif
}
NonnullOwnPtr(NonnullOwnPtr const&) = delete;
template<typename U>
NonnullOwnPtr(NonnullOwnPtr<U> const&) = delete;
NonnullOwnPtr& operator=(NonnullOwnPtr const&) = delete;
template<typename U>
NonnullOwnPtr& operator=(NonnullOwnPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr(RefPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr(NonnullRefPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr(WeakPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr& operator=(RefPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr& operator=(NonnullRefPtr<U> const&) = delete;
template<typename U>
NonnullOwnPtr& operator=(WeakPtr<U> const&) = delete;
NonnullOwnPtr& operator=(NonnullOwnPtr&& other)
{
NonnullOwnPtr ptr(move(other));
swap(ptr);
return *this;
}
template<typename U>
NonnullOwnPtr& operator=(NonnullOwnPtr<U>&& other)
{
NonnullOwnPtr ptr(move(other));
swap(ptr);
return *this;
}
[[nodiscard]] T* leak_ptr()
{
return exchange(m_ptr, nullptr);
}
ALWAYS_INLINE RETURNS_NONNULL T* ptr() const
{
VERIFY(m_ptr);
return m_ptr;
}
ALWAYS_INLINE RETURNS_NONNULL T* operator->() const { return ptr(); }
ALWAYS_INLINE T& operator*() const { return *ptr(); }
ALWAYS_INLINE RETURNS_NONNULL operator T*() const { return ptr(); }
operator bool() const = delete;
bool operator!() const = delete;
void swap(NonnullOwnPtr& other)
{
::swap(m_ptr, other.m_ptr);
}
template<typename U>
void swap(NonnullOwnPtr<U>& other)
{
::swap(m_ptr, other.m_ptr);
}
template<typename U>
NonnullOwnPtr<U> release_nonnull()
{
VERIFY(m_ptr);
return NonnullOwnPtr<U>(NonnullOwnPtr<U>::Adopt, static_cast<U&>(*leak_ptr()));
}
private:
void clear()
{
if (!m_ptr)
return;
delete m_ptr;
m_ptr = nullptr;
}
T* m_ptr = nullptr;
};
#if !defined(KERNEL)
template<typename T>
inline NonnullOwnPtr<T> adopt_own(T& object)
{
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, object);
}
template<class T, class... Args>
requires(IsConstructible<T, Args...>) inline NonnullOwnPtr<T> make(Args&&... args)
{
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, *new T(forward<Args>(args)...));
}
// FIXME: Remove once P0960R3 is available in Clang.
template<class T, class... Args>
inline NonnullOwnPtr<T> make(Args&&... args)
{
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, *new T { forward<Args>(args)... });
}
#endif
// Use like `adopt_nonnull_own_or_enomem(new (nothrow) T(args...))`.
template<typename T>
inline ErrorOr<NonnullOwnPtr<T>> adopt_nonnull_own_or_enomem(T* object)
{
if (!object)
return Error::from_errno(ENOMEM);
return NonnullOwnPtr<T>(NonnullOwnPtr<T>::Adopt, *object);
}
template<typename T, class... Args>
requires(IsConstructible<T, Args...>) inline ErrorOr<NonnullOwnPtr<T>> try_make(Args&&... args)
{
return adopt_nonnull_own_or_enomem(new (nothrow) T(forward<Args>(args)...));
}
// FIXME: Remove once P0960R3 is available in Clang.
template<typename T, class... Args>
inline ErrorOr<NonnullOwnPtr<T>> try_make(Args&&... args)
{
return adopt_nonnull_own_or_enomem(new (nothrow) T { forward<Args>(args)... });
}
template<typename T>
struct Traits<NonnullOwnPtr<T>> : public GenericTraits<NonnullOwnPtr<T>> {
using PeekType = T*;
using ConstPeekType = T const*;
static unsigned hash(NonnullOwnPtr<T> const& p) { return ptr_hash(p.ptr()); }
static bool equals(NonnullOwnPtr<T> const& a, NonnullOwnPtr<T> const& b) { return a.ptr() == b.ptr(); }
};
template<typename T, typename U>
inline void swap(NonnullOwnPtr<T>& a, NonnullOwnPtr<U>& b)
{
a.swap(b);
}
template<typename T>
struct Formatter<NonnullOwnPtr<T>> : Formatter<T const*> {
ErrorOr<void> format(FormatBuilder& builder, NonnullOwnPtr<T> const& value)
{
return Formatter<T const*>::format(builder, value.ptr());
}
};
}
#if USING_AK_GLOBALLY
# if !defined(KERNEL)
using AK::adopt_own;
using AK::make;
# endif
using AK::adopt_nonnull_own_or_enomem;
using AK::NonnullOwnPtr;
using AK::try_make;
#endif