OwnedFd.hpp

// SPDX-FileCopyrightText: 2025 Vincent Leroy
// SPDX-License-Identifier: MIT
//
// This file is part of dfx.
//
// Licensed under the MIT License. See the LICENSE file in the project root
// for full license information.
 
#pragma once
 
// Standard includes
#include <format>
 
// Project includes
#include "BorrowedFd.hpp"
#include <dfx-utilities/CopyMoveControl.hpp>
 
namespace dfx::FdWatch
{
class OwnedFd
{
public:
    OwnedFd() noexcept;

    explicit OwnedFd(int fd) noexcept;

    OwnedFd(OwnedFd && other) noexcept;
 
    DISABLE_COPY(OwnedFd);

    ~OwnedFd();

    OwnedFd & operator=(OwnedFd && other) noexcept;
 
    // Comparing 2 OwnedFd doesn't make sense since a OwnedFd owns its fd int
    // so if 2 are equals it means that there is a bug somewhere
    bool operator==(OwnedFd const &) const noexcept = delete;
    bool operator!=(OwnedFd const &) const noexcept = delete;
 
    bool operator==(int fd) const noexcept                { return _fd == fd; }
    bool operator==(BorrowedFd const & fd) const noexcept { return _fd == fd.get(); }
 
    void swap(OwnedFd & other) noexcept;

    bool isValid() const noexcept { return _fd != -1; }

    int get() const noexcept      { return _fd; }

    void close() noexcept;

    int release() noexcept;

    void reset(int newFd = -1) noexcept;

    [[nodiscard]] BorrowedFd borrow() const noexcept { return BorrowedFd(*this); }
 
private:
    int _fd = -1;
};

[[nodiscard]] inline OwnedFd makeOwnedFd(int fd) noexcept { return OwnedFd(fd); }
inline void swap(OwnedFd & fd1, OwnedFd & fd2) noexcept   { fd1.swap(fd2); }
} // !namespace dfx::FdWatch
 
template<>
struct std::formatter<dfx::FdWatch::OwnedFd> : public formatter<int>
{
    auto format(dfx::FdWatch::OwnedFd const & e, format_context & ctx) const
    { return formatter<int>::format(e.get(), ctx); }
};