Arbutils/src/Memory/borrowed_ptr.hpp

#ifndef ARBUTILS_BORROWED_PTR_HPP
#define ARBUTILS_BORROWED_PTR_HPP

#include <memory>

/// A borrowed pointer is used to indicate a pointer that is not owned by an object, but instead borrowed from another
/// owning object that is assumed to always be kept alive during the entire lifetime of the borrowing object.
template <class T> class borrowed_ptr {
private:
    T* _raw;

public:
    inline borrowed_ptr<T>() : _raw(nullptr){};
    inline borrowed_ptr<T>(T* ptr) : _raw(ptr){};
    inline borrowed_ptr(const borrowed_ptr<T>& other) : _raw(other._raw){};
    inline borrowed_ptr(const std::unique_ptr<T>& other) : _raw(other.get()){};

    ~borrowed_ptr() = default;

    inline borrowed_ptr<T>& operator=(const borrowed_ptr<T>& rhs) {
        _raw = rhs._raw;
        return *this;
    }

    inline T* operator->() const noexcept { return _raw; }
    inline T* GetRaw() const noexcept { return _raw; }

    inline bool operator==(const borrowed_ptr& rhs) const { return _raw == rhs._raw; }
    inline bool operator!=(const borrowed_ptr& rhs) const { return _raw != rhs._raw; }

    [[nodiscard]] inline constexpr bool IsNull() const noexcept { return _raw == nullptr; }
};

#endif // ARBUTILS_BORROWED_PTR_HPP