windows-user-space-emulator/src/common/utils/nt_handle.hpp

#pragma once

#ifdef WIN32

#include "win.hpp"

#include <type_traits>

namespace utils::nt
{
    using HandleFunction = HANDLE();

    inline HANDLE null_handle()
    {
        return nullptr;
    }

    inline HANDLE invalid_handle()
    {
        return INVALID_HANDLE_VALUE;
    }

    template <HandleFunction InvalidHandleFunction = null_handle>
    class handle
    {
      public:
        handle() = default;

        handle(const HANDLE h)
            : handle_(h)
        {
        }

        ~handle()
        {
            if (*this)
            {
                CloseHandle(this->handle_);
                this->handle_ = InvalidHandleFunction();
            }
        }

        handle(const handle&) = delete;
        handle& operator=(const handle&) = delete;

        handle(handle&& obj) noexcept
            : handle()
        {
            this->operator=(std::move(obj));
        }

        handle& operator=(handle&& obj) noexcept
        {
            if (this != &obj)
            {
                this->~handle();
                this->handle_ = obj.handle_;
                obj.handle_ = InvalidHandleFunction();
            }

            return *this;
        }

        handle& operator=(HANDLE h) noexcept
        {
            this->~handle();
            this->handle_ = h;

            return *this;
        }

        [[nodiscard]] operator bool() const
        {
            return this->handle_ != InvalidHandleFunction();
        }

        [[nodiscard]] operator HANDLE() const
        {
            return this->handle_;
        }

      private:
        HANDLE handle_{InvalidHandleFunction()};
    };
}

#endif