maple_util/include/ptr.h

/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * 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 MAPLE_UTIL_PTR_H
#define MAPLE_UTIL_PTR_H
#include <functional>

namespace maple {
namespace utils {
template <typename T>
using PtrCheckerType = void (*)(const T *);

template <typename T>
inline constexpr void CheckNothing(const T *)
{
}

template <typename T, PtrCheckerType<T> Check = CheckNothing<T>>
class Ptr {
public:
    using Pointer = T *;
    using ElementType = T;

    constexpr Ptr() noexcept : pointer(nullptr)
    {
        Check(nullptr);
    }

    constexpr explicit Ptr(std::nullptr_t) noexcept : pointer(nullptr)
    {
        Check(nullptr);
    }

    explicit Ptr(Pointer ptr) : pointer(ptr)
    {
        Check(ptr);
    }

    Ptr(Pointer ref, PtrCheckerType<T> checker) : pointer(ref)
    {
        checker(pointer);
    }

    explicit Ptr(T &ref) : pointer(&ref)
    {
        Check(pointer);
    }

    Ptr(T &ref, PtrCheckerType<T> checker) : pointer(&ref)
    {
        checker(pointer);
    }

    explicit Ptr(T &&ref) = delete;

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    explicit Ptr(U *ptr) : pointer(ptr)
    {
        Check(pointer);
    }

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    explicit Ptr(U &ref) : pointer(&ref)
    {
        Check(pointer);
    }

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    Ptr(U &ref, PtrCheckerType<T> checker) : pointer(&ref)
    {
        checker(pointer);
    }

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    explicit Ptr(U &&ref) = delete;

    explicit Ptr(const Ptr &other) : pointer(other.get()) {}

    explicit Ptr(Ptr &&other) noexcept : pointer(other.get()) {}

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    explicit Ptr(const Ptr<U, CheckU> &other) : pointer(other.get())
    {
        Check(pointer);
    }

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    Ptr(const Ptr<U, CheckU> &other, PtrCheckerType<T> checker) : pointer(other.get())
    {
        checker(pointer);
    }

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    explicit Ptr(Ptr<U, CheckU> &&other) : pointer(other.get())
    {
        Check(pointer);
    }

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    Ptr(Ptr<U, CheckU> &&other, PtrCheckerType<T> checker) : pointer(other.get())
    {
        checker(pointer);
    }

    ~Ptr() = default;

    Ptr &operator=(Pointer ptr) noexcept
    {
        Check(ptr);
        pointer = ptr;
        return *this;
    }

    Ptr &operator=(std::nullptr_t) noexcept
    {
        Check(nullptr);
        reset();
        return *this;
    }

    Ptr &operator=(const Ptr &ptr) noexcept
    {
        if (&ptr != this) {
            pointer = ptr.pointer;
        }
        return *this;
    }

    Ptr &operator=(Ptr &&ptr) noexcept
    {
        if (&ptr != this) {
            pointer = std::move(ptr.pointer);
        }
        return *this;
    }

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    Ptr &operator=(const Ptr<U, CheckU> &ptr) noexcept
    {
        if (this->get() != ptr.get()) {
            Check(ptr.get());
            pointer = ptr.get();
        }
        return *this;
    }

    template <typename U, PtrCheckerType<U> CheckU, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    Ptr &operator=(Ptr<U, CheckU> &&ptr) noexcept
    {
        if (this->get() != ptr.get()) {
            Check(ptr.get());
            pointer = std::move(ptr.get());
        }
        return *this;
    }

    Pointer release() noexcept = delete;

    void reset(Pointer ptr = Pointer()) noexcept
    {
        Check(ptr);
        pointer = ptr;
    }

    void swap(Ptr &other) noexcept
    {
        std::swap(pointer, other.pointer);
    }

    T *get() const noexcept
    {
        return pointer;
    }

    explicit operator bool() const noexcept
    {
        return get() != nullptr;
    }

    T &operator*() const
    {
        return *get();
    }

    T *operator->() const noexcept
    {
        return get();
    }

    T &operator[](size_t i) const = delete;

    Ptr &operator++() = delete;

    const Ptr operator++(int) = delete;

    Ptr &operator--() = delete;

    const Ptr operator--(int) = delete;

    Ptr &operator+=(std::ptrdiff_t) = delete;

    Ptr &operator-=(std::ptrdiff_t) = delete;

private:
    T *pointer;
};

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator==(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return lhs.get() == rhs.get();
}

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator!=(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return !(lhs == rhs);
}

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator<(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return lhs.get() < rhs.get();
}

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator<=(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return lhs.get() <= rhs.get();
}

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator>(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return !(lhs <= rhs);
}

template <typename T, PtrCheckerType<T> CheckT, typename U, PtrCheckerType<U> CheckU>
inline bool operator>=(const Ptr<T, CheckT> &lhs, const Ptr<U, CheckU> &rhs)
{
    return !(lhs < rhs);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator==(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return !static_cast<bool>(lhs);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator==(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return !static_cast<bool>(rhs);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator!=(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return static_cast<bool>(lhs);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator!=(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return static_cast<bool>(rhs);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator<(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return std::less<typename Ptr<T, CheckT>::Pointer>()(lhs.get(), nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator<(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return std::less<typename Ptr<T, CheckT>::Pointer>()(nullptr, rhs.get());
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator<=(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return !(lhs > nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator<=(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return !(rhs < nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator>(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return !(lhs <= nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator>(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return !(rhs >= nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator>=(const Ptr<T, CheckT> &lhs, std::nullptr_t)
{
    return !(lhs < nullptr);
}

template <typename T, PtrCheckerType<T> CheckT>
inline bool operator>=(std::nullptr_t, const Ptr<T, CheckT> &rhs)
{
    return !(rhs > nullptr);
}
}  // namespace utils
}  // namespace maple
#endif  // DIY_CPLUSPLUS_SAFE_PTR_H